How to calculate a percentage of a sum: percentage, discount and VAT calculators
Change the numbers – the answer and the formula in words update at once. A word problem about a deposit or a loan is solved by the AI in the chat.
%Percentage of a sum
15% of 2,400 = 2,400 × 15 ÷ 100 = 360
?What percentage is it
360 ÷ 2,400 × 100 = 15%
−Discount
3,500 × (100 − 20) ÷ 100 = 2,800
+Markup and margin
Markup = (1,500 − 1,000) ÷ 1,000 × 100; margin = (1,500 − 1,000) ÷ 1,500 × 100
НVAT
122,000 × 22 ÷ 122 = 22,000
A word problem – to the chat
A deposit, a loan, compound interest: the AI solves it step by stepPrompt sent to the chat: «Solve this percentage problem and explain it step by step, with the formula and a check. Show how to calculate it on a phone calculator. The problem: A deposit of 200,000 ₽ at 12% a year with monthly compounding for 1 year. How much will there be at the end, and how much of it is interest?»
You can photograph a problem from a textbook or a contract. Free on the Starter plan.
Solve the problem in the chatHow to calculate a percentage on a phone calculator
Three ways on the example of 15% of 2,400. The first does not work on every calculator; the second and the third work on any, including the ordinary smartphone app and the scientific mode.
If no result appears, press “=”. For a discount: 3500 − 20% gives the price after the discount at once.
15% is 0.15. The sum plus the percentage: × 1.15, minus it: × 0.85.
First find 1% – a hundredth of the sum – then multiply by the number of percent. It helps when the percentage is not whole, for example 7.5%.
Percentage formulas in Excel
Type a percentage into a cell as 15% – Excel stores it as 0.15. For a share, give the cell the “Percentage” format. Write a formula once and drag it down the column – the cell references adjust themselves.
| A | B | C | What it counts | |
|---|---|---|---|---|
| 2 | 2,400 | 15% | =A2*B2 → 360 | a percentage of a number |
| 3 | 360 | 2,400 | =A3/B3 → 15% | what percentage it is |
| 4 | 3,500 | 20% | =A4*(1-B4) → 2,800 | subtract a percentage, a discount |
| 5 | 1,000 | 22% | =A5*(1+B5) → 1,220 | add a percentage |
| 6 | 1,000 | 1,500 | =(B6-A6)/A6 → 50% | change, markup |
How to calculate 5, 10, 13, 20 and 22 percent of a sum
The table is counted from the sum in the first calculator. Change it there and the row below updates.
Move the decimal point one place left: of 2,400 that is 240.
Half of 10%: 240 ÷ 2 = 120.
Two lots of 10%: 240 × 2 = 480.
10% plus 3%: 240 + 72 = 312.
Four mistakes that make a percentage come out wrong
The formulas are simple, but in a shop, a report or a contract percentages are often added and subtracted on the wrong sum. Check yourself on the examples.
A discount on a discount
The second discount is taken from the already reduced price. From 1,000 ₽, 20% leaves 800, another 10% leaves 720, not 700. The total discount is 28%.
Rise and fall
A price of 1,000 rose 10% to 1,100. It fell 10% to 990. Each time the percentage is taken from the new sum, so the price does not return to the original.
Which price to count from
Markup is counted on the cost, margin on the sale price. The same 500 ₽ profit gives a 50% markup and a margin of about 33%.
Extracting VAT
If 122,000 ₽ already includes the tax, you cannot multiply by 22%: that gives 26,840. The right way is 122,000 × 22 ÷ 122 = 22,000.
The percentage calculators and problem solving are free
Starter – 0 ₽
The five calculators on the page work without signing up. A word problem in the chat is a text request, included in the free plan with 30 units of energy. For frequent use there is Lite at ₽690 (150 energy) and Basic at ₽990 (200 energy).
FAQ
How do I calculate a percentage of a sum?
Multiply the sum by the number of percent and divide by 100. For example, 15% of 2,400: 2,400 × 15 ÷ 100 = 360. In the calculator above it is the first card.
How do I calculate a discount in percent?
Multiply the price by (100 − discount) and divide by 100: 3,500 with a 20% discount is 3,500 × 80 ÷ 100 = 2,800. The saving is the difference from the original price, 700.
How do I calculate 22% VAT of a sum?
To extract VAT from a sum that includes it, multiply the sum by 22 and divide by 122. To add it on top, multiply the sum without VAT by 0.22. The reduced 10% rate (food, children’s goods, medicines) and the 7% and 5% rates for the simplified tax system work the same way – switch them in the “VAT” card. Russian VAT is 22% in 2026.
How do I calculate a markup?
Markup is the difference between the sale price and the cost, divided by the cost, × 100%. Margin is the same difference divided by the sale price. With a cost of 1,000 and a sale price of 1,500 the markup is 50% and the margin about 33%.
How do I calculate 13 percent of a sum?
Multiply the sum by 0.13, or find 10% and add 3%. For example, 13% of 85,000 is 8,500 + 2,550 = 11,050. The same works for 5, 10, 20 and 30 percent: the table under the calculator does it for your sum.
How do I calculate a percentage of a sum in Excel?
Enter the sum in A2, the percentage in B2 as 15%, and write =A2*B2 in C2. A share is counted with =A3/B3 and the percentage cell format.
How do I calculate the annual interest on a deposit or a loan?
Without compounding: sum × rate ÷ 100 × years. With monthly compounding, and for loan payments, the formula is harder – describe the problem in words in the field above and the AI solves it step by step.
Percentages without scratch paper or doubt
Simple ones right on the page, wordy ones with a catch in the chat.
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