How to calculate interest. How to calculate (calculate) the percentage of the amount? How to calculate the discounted price

One of the most common ways to increase sales is to provide a discount. The seller announces the amount of reduction in the price of the goods, and the buyer decides whether he is satisfied with the new price or not. However, not everyone can immediately figure out how to calculate a discount on a product in order to evaluate the terms of the deal. For the buyer, the final amount of the purchase is important, and for the seller, profit is important. Here is the formula for calculating the discount.

Why are discounts introduced?

Usually prices are reduced to attract new customers or increase sales volumes. Sellers are developing pricing policy, taking into account:

seasonality of sales - price changes during periods of greatest or, conversely, least demand;

volumes, frequency of transactions;

payment terms (for example, reduction for advance payment methods).

Discounts can be provided to all counterparties without exception or only to those in whom the seller is interested.

Reason for providing discount

In Art. 424 of the Civil Code of the Russian Federation states that the price is set by agreement of the parties. Changes are permitted under the terms of the concluded agreement, or in cases specified by law (clauses 1, 2 of Article 424 of the Civil Code of the Russian Federation).

In retail, the discount amount is usually indicated in the price tag for the product for which the offer is valid. To attract buyers, they place an additional advertisement about the current promotion. The total amount is indicated on the receipt taking into account all discounts.

WITH wholesale buyers the terms of the transaction are specified in the text of the contract. The possibility of providing discounts must be explicitly stated in the document. From the concluded agreement it should be clear how to calculate a discount on a product if the counterparty has met the conditions for a price reduction.

How to apply for a discount

The seller can provide a discount immediately, at the time of purchasing a product or service, or later - after fulfilling additional conditions, for example, after reaching a certain volume of purchases. Depending on this, the following documents are issued:

if the discount is provided immediately, then the price including the discount is indicated in the documents;

if the discount is granted later, adjustment documents are drawn up.

Price deviation may be of interest to tax authorities - clause 2 of Art. 40 of the Tax Code of the Russian Federation allows inspectors to check the correctness of price calculations when they change by more than 20% compared to the prices used by the seller for identical goods in a short period of time.

Where are discounts reflected?

Price changes must be recorded in documents. Which documents should contain information about discounts:

in the company’s internal documents (price lists, list of goods, etc.);

in contracts with counterparties;

in documents prepared upon shipment (waybills, invoices, UPD):

if necessary - in adjustment documents;

Reducing prices entails the need to take into account the changed data in accounting and tax accounting. The information is also reflected in tax returns.

How to calculate a discount on a product, formula

If the buyer is only aware of the size of the base, initial price, knowing the amount of the discount, it is possible to calculate both the amount of the discount and the new cost of the product.

Most often, the discount is indicated as a percentage. How to correctly calculate a discount on a product? The formula applied is as follows:

SS = BC / 100% x PS, where

СС - discount amount,

BC - base price,

PS - % discount.

To find out the new price, from base cost deduct the discount amount received.

Let's give an example of a calculation.

An example of calculating a discount based on a set percentage

Urozhay LLC has been selling apples since the beginning of the year at a price of 40 rubles per kilogram. In August, due to a seasonal decrease in demand for goods, the company announced a 15% discount to customers. How to correctly calculate a discount on a product?

40 rubles is the base price,

15% is the discount percentage.

The amount of price reduction will be: 40 / 100% x 15% = 6 rubles.

The price for apples in August, taking into account the discount provided, will be: 40 – 6 = 34 rubles per kilogram.

Fixed discount

Sometimes the seller announces a discount in a fixed amount. Then the buyer can calculate the discount amount as a percentage in reverse order:

PS = ((BC – NC) / BC) x 100%, where

PS – discount percentage;

BC – base (old) price;

NC – new price.

Here is the calculation of the discount.

An example of calculating the discount percentage based on a fixed value

The supply agreement between Aqua LLC and Vega LLC stipulates that the cost of delivery of bottled water for a 19 liter container under the agreement is 160 rubles. If the monthly delivery volume exceeds 190 liters, the delivery cost will be lower and amount to 150 rubles. Let's calculate the discount percentage if the condition for exceeding the supply volume is met:

160 rub. – base price,

150 rub. – new price.

The discount percentage will be: ((160 – 150) / 160) x 100% = 6.25%.

That is, the cost is reduced by 6.25% if more than 190 liters of water per month are delivered under the contract.

Using these formulas, the buyer can independently calculate the amount of price change, as well as calculate the new cost of the product. This will help you decide whether it is worth concluding a deal on the proposed terms.

How to calculate the percentage of the amount, you need to know in many cases (when calculating state duties, loans, etc.). We will tell you how to calculate percentages of an amount using a calculator, proportions and known ratios.

How to find out the percentage of the amount in the general case?

After this there are two options:

1. If you want to find out what percentage another amount is from the original, you just need to divide it by the 1% amount obtained earlier.
2. If you need an amount that is, say, 27.5% of the original, you need to multiply the amount of 1% by the required amount of interest.

How to calculate a percentage of an amount using a proportion?

But you can do it differently. To do this, you will have to use knowledge about the method of proportions, which is taught as part of the school mathematics course. It will look like this.

Let us have A - the main amount equal to 100%, and B - the amount whose relationship with A as a percentage we need to find out. We write down the proportion:

(X in this case is the number of percent).

According to the rules for calculating proportions, we obtain the following formula:

Don't know your rights?

X = 100 * V / A

If you need to find out how much the amount B will be if the number of percentages of the amount A is already known, the formula will look different:

B = 100 * X / A

Now all that remains is to substitute known numbers into the formula - and you can make the calculation.

How to calculate the percentage of an amount using known ratios?

Finally, you can use more in a simple way. To do this, just remember that 1% as a decimal is 0.01. Accordingly, 20% is 0.2; 48% - 0.48; 37.5% is 0.375, etc. It is enough to multiply the original amount by the corresponding number - and the result will indicate the amount of interest.

In addition, sometimes you can use simple fractions. For example, 10% is 0.1, that is, 1/10; therefore, finding out how much 10% is is simple: you just need to divide the original amount by 10.

Other examples of such relationships would be:

• 12.5% ​​- 1/8, that is, you need to divide by 8;
• 20% - 1/5, that is, you need to divide by 5;
• 25% - 1/4, that is, divide by 4;
• 50% - 1/2, that is, it needs to be divided in half;
• 75% is 3/4, that is, you need to divide by 4 and multiply by 3.

True, not all simple fractions are convenient for calculating percentages. For example, 1/3 is close in size to 33%, but not exactly equal: 1/3 is 33.(3)% (that is, a fraction with infinite threes after the decimal point).

How to subtract a percentage from an amount without using a calculator

If you need to subtract an unknown number, which is a certain amount of percent, from an already known amount, you can use the following methods:

1. Calculate the unknown number using one of the above methods, and then subtract it from the original one.
2. Immediately calculate the remaining amount. To do this, subtract from 100% the number of percentages that need to be subtracted, and convert the resulting result from percentage to number using any of the methods described above.

The second example is more convenient, so let’s illustrate it. Let's say we need to find out how much is left if we subtract 16% from 4779. The calculation will be like this:

1. We subtract 16 from 100 (the total number of percent). We get 84.
2. We calculate how much 84% of 4779 is. We get 4014.36.

How to calculate (subtract) a percentage from a sum with a calculator in hand

All of the above calculations are easier to do using a calculator. It can be either in the form of a separate device or in the form of a special program on a computer, smartphone or regular mobile phone (even the oldest devices currently in use usually have this function). With their help, the question of how to calculate the percentage of an amount is solved very simply:

1. The initial amount is collected.
2. The “-” sign is pressed.
3. Enter the number of percentages you want to subtract.
4. The “%” sign is pressed.
5. The “=” sign is pressed.

As a result, the required number is displayed on the screen.

How to subtract a percentage from an amount using an online calculator

Finally, there are now quite a few sites on the Internet that offer an online calculator function. In this case, you don’t even need to know how to calculate the percentage of the amount: all user operations are reduced to entering the required numbers in the windows (or moving the sliders to get them), after which the result is immediately displayed on the screen.

This function is especially convenient for those who calculate not just an abstract percentage, but a specific amount of tax deduction or the amount of state duty. The fact is that in this case the calculations are more complicated: you not only need to find the percentages, but also add a constant part of the amount to them. An online calculator allows you to avoid such additional calculations. The main thing is to choose a site that uses data that complies with the current law.

Good day!

Interest, I tell you, is not only something “boring” in mathematics lessons at school, but also an extremely necessary and practical thing in life (found everywhere: when you take out a loan, open a deposit, calculate profits, etc. ). And in my opinion, when studying the topic of “percentages” in the same school, extremely little time is devoted to this ().

Perhaps because of this, some people find themselves in not very pleasant situations (many of which could have been avoided if they had figured out what was there and how in time...).

Actually, in this article I want to look at the most popular problems with percentages that occur in life (of course, I will consider this as much as possible in simple language with examples). Well, forewarned means forearmed (I think that knowledge of this topic will save many people both time and money).

And so, closer to the topic...

Option 1: calculate prime numbers in your head in 2-3 seconds.

In the vast majority of cases in life, you need to quickly estimate in your mind how much a 10% discount on a certain number (for example) will be. Agree, in order to make a purchasing decision, you don’t need to calculate everything down to the penny (it’s important to figure out the order).

The most common variants of numbers with percentages are given in the list below, as well as what you need to divide the number by to find out the desired value.

Simple examples:

• 1% of the number = divide the number by 100 (1% of 200 = 200/100 = 2);
• 10% of a number = divide the number by 10 (10% of 200 = 200/10 = 20);
• 25% of a number = divide the number by 4 or twice by 2 (25% of 200 = 200/4 = 50);
• 33% of the number ≈ divide the number by 3;
• 50% of a number = divide the number by 2.

Problem! For example, you want to buy equipment for 197 thousand rubles. The store offers a 10.99% discount if you meet certain conditions. How can you quickly figure out if it’s worth it?

Example solution. Yes, just round these pair of numbers: instead of 197, take the amount of 200, instead of 10.99%, take 10% (conditionally). In total, you need to divide 200 by 10 - i.e. we estimated the size of the discount at approximately 20 thousand rubles. (with some experience, the calculation is done almost automatically in 2-3 seconds).

Exact calculation: 197 * 10.99/100 = 21.65 thousand rubles.

Option 2: use the Android phone calculator

When you need a more accurate result, you can use a calculator on your phone (in the article below I will give screenshots from Android). It's quite simple to use.

For example, you need to find 30% of the number 900. How to do this?

Yes, quite simple:

• open the calculator;
• write 30%900 (of course, the percentage and number can be different);
• Please note that below your written “equation” you will see the number 270 - this is 30% of 900.

Below is a more complex example. We found 17.39% of the number 393,675 (result 68460, 08).

If you need, for example, to subtract 10% from 30,000 and find out how much it will be, then you can write it like this (by the way, 10% of 30,000 is 3000). Thus, if you subtract 3000 from 30,000, you will get 27,000 (which is what the calculator showed).

In general, it is a very convenient tool when you need to calculate 2-3 numbers and get accurate results, down to tenths/hundredths.

Option 3: count the percentage of the number (the essence of the calculation + the golden rule)

It is not always and not everywhere possible to round numbers and calculate percentages in your head. Moreover, sometimes it is necessary not only to obtain some exact result, but also to understand the very “essence of the calculation” (for example, to calculate a hundred/thousand different problems in Excel).

Let's say we need to find 17.39% of the number 393,675. Let's solve this simple problem...

To remove all the points on "Y", I will consider the inverse problem. For example, what percentage is the number 30,000 from the number 393,675.

Option 4: calculate percentages in Excel

Excel is good because it allows you to make fairly voluminous calculations: you can simultaneously calculate dozens of different tables by linking them together. And in general, is it possible to manually calculate percentages for dozens of items of goods, for example.

Below I will show a couple of examples that you most often encounter.

Problem one. There are two numbers, for example, the purchase and sale price. You need to find out the difference between these two numbers as a percentage (how much more/less one is than the other).

For a more precise understanding, I will give one more example. Another problem: there is a purchase price and the desired percentage of profit (let's say 10%). How to find out the selling price. Everything seems to be simple, but many people “stumble”...

Additions on the topic are always welcome...

That's all, good luck!

A percentage is one hundredth of a number taken as a whole. Percentages are used to indicate the relationship of a part to the whole, as well as to compare quantities.

1% = 1 100 = 0,01

The interest calculator allows you to perform the following operations:

Find the percentage of a number

To find the percentage p from a number, you need to multiply this number by a fraction p 100

Let's find 12% of the number 300:
300 12 100 = 300 · 0.12 = 36
12% of 300 is 36.

For example, a product costs 500 rubles and there is a 7% discount on it. Let's find the absolute value of the discount:
500 7 100 = 500 · 0.07 = 35
Thus, the discount is 35 rubles.

What percentage is one number of another?

To calculate the percentage of numbers, you need to divide one number by another and multiply by 100%.

Let's calculate what percentage the number 12 is from the number 30:
12 30 · 100 = 0.4 · 100 = 40%
The number 12 is 40% of the number 30.

For example, a book contains 340 pages. Vasya read 200 pages. Let's calculate what percentage of the entire book Vasya read.
200 340 · 100% = 0.59 · 100 = 59%
Thus, Vasya read 59% of the entire book.

Add percentage to number

To add to a number p percent, you need to multiply this number by (1 + p 100)

Add 30% to the number 200:
200 (1 + 30 100 ) = 200 1.3 = 260
200 + 30% equals 260.

For example, a swimming pool subscription costs 1000 rubles. Starting next month they promised to raise the price by 20%. Let's calculate how much a subscription will cost.
1000 (1 + 20 100 ) = 1000 1.2 = 1200
Thus, the subscription will cost 1200 rubles.

Subtract the percentage from the number

To subtract from a number p percent, you need to multiply this number by (1 - p 100)

Subtract 30% from the number 200:
200 (1 - 30 100 ) = 200 · 0.7 = 140
200 - 30% equals 140.

For example, a bicycle costs 30,000 rubles. The store gave it a 5% discount. Let's calculate how much the bike will cost taking into account the discount.
30000 · (1 - 5 100 ) = 30000 0.95 = 28500
Thus, the bike will cost 28,500 rubles.

What percentage is one number greater than another?

To calculate how many percent one number is greater than another, you need to divide the first number by the second, multiply the result by 100 and subtract 100.

Let's calculate how many percent the number 20 is greater than the number 5:
20 5 · 100 - 100 = 4 · 100 - 100 = 400 - 100 = 300%
The number 20 is 300% greater than the number 5.

For example, the boss’s salary is 50,000 rubles, and the employee’s salary is 30,000 rubles. Let's find out how many percent the boss's salary is greater:
50000 35000 · 100 - 100 = 1.43 * 100 - 100 = 143 - 100 = 43%
Thus, the boss's salary is 43% higher than the employee's salary.

What percentage is one number less than another?

To calculate how many percent one number is less than another, you need to subtract from 100 the ratio of the first number to the second, multiplied by 100.

Let's calculate how many percent the number 5 is less than the number 20:
100 - 5 20 · 100 = 100 - 0.25 · 100 = 100 - 25 = 75%
The number 5 is 75% less than the number 20.

For example, freelancer Oleg completed orders worth 40,000 rubles in January, and 30,000 rubles in February. Let's find how many percent less Oleg earned in February than in January:
100 - 30000 40000 · 100 = 100 - 0.75 * 100 = 100 - 75 = 25%
Thus, in February Oleg earned 25% less than in January.

Find 100 percent

If the number x This p percent, then you can find 100 percent by multiplying the number x on 100p

Let's find 100% if 25% is 7:
7 · 100 25 = 7 4 = 28
If 25% equals 7, then 100% equals 28.

For example, Katya copies photos from her camera to her computer. In 5 minutes, 20% of the photos were copied. Let's find how long the copying process takes:
5 · 100 20 = 5 5 = 25
We find that the process of copying all photos takes 25 minutes.

In mathematics, a percentage is one hundredth of a number. For example, 5% of 100 is 5.
This calculator will allow you to accurately calculate the percentage of a given number. There are various calculation modes available. You will be able to make various calculations using percentages.

• The first calculator is needed when you want to calculate the percentage of the amount. Those. Do you know the meaning of percentage and amount?
• The second one is if you need to calculate what percentage X is of Y. X and Y are numbers, and you are looking for the percentage of the first in the second
• The third mode is adding a percentage of the specified number to the given number. For example, Vasya has 50 apples. Misha brought Vasya another 20% of the apples. How many apples does Vasya have?
• The fourth calculator is the opposite of the third. Vasya has 50 apples, and Misha took 30% of the apples. How many apples does Vasya have left?

Frequent tasks

Solution: We use the first calculator. Enter the bet 6 in the first field, 100000 in the second
We receive 6,000 rubles. - tax amount.

Problem 2. Misha has 30 apples. He gave 6 to Katya. What percentage of the total number of apples did Misha give to Katya?

Solution: We use the second calculator - enter 6 in the first field, 30 in the second. We get 20%.

Task 3. At Tinkoff Bank, for replenishing a deposit from another bank, the depositor receives 1% on top of the replenishment amount. Kolya replenished the deposit with a transfer from another bank in the amount of 30,000. What is the total amount for which Kolya’s deposit will be replenished?

Bank interest calculators

Calculation algorithms

• Subtract the final price from the initial price and determine the discount in rubles C = 50 - 30 = 20
• Discount in rubles C divided by the starting price A and multiplied by 100%, Discount percentage = 100* 20/50 = 40%