Increase a Number by a Percentage Calculator

Need to add a percentage to a number? Enter the starting number and the percentage you want to increase it by, and NumoCrunch will instantly calculate the new value.

Formula: X × (1 + Y ÷ 100)

X = original number · Y = percentage increase

Starting number (X)

Enter starting number to see your answer.

Increase by (Y %)

Example: 20 adds 20%.

New value

—

Amount added: —
New value as a share of the original: —

Original—Increase—

Enter your numbers above to see each step worked out with your values.

Questions This Calculator Can Answer

Not sure how to phrase your calculation? Try one of these real-world examples. Tap any example to load it into the calculator.

How to increase a number by a percentage

Convert the percentage to a decimal, add it to 1, and multiply the result by the original number.

New Value = Original Value × (1 + Percentage ÷ 100)

To increase 800 by 15%: 15 ÷ 100 = 0.15, then 1 + 0.15 = 1.15, then 800 × 1.15 = 920. The amount added is 920 − 800 = 120. The same steps increase $250 by 20%: 250 × 1.20 = $300, an increase of $50.

Quick percentage increase examples

Original	Increase	New value
100	10%	110
100	25%	125
200	20%	240
500	15%	575
1,000	30%	1,300
2,500	12%	2,800

What does it mean to increase a number by a percentage?

It means adding a proportion of the original value on top of itself. 20% of 500 is 100, so increasing 500 by 20% gives 500 + 100 = 600.

That is different from adding the percentage number itself: 500 increased by 20% is 600, not 500 + 20 = 520.

Common uses for percentage increases

Salary raises
Price increases
Budget growth
Revenue forecasts
Sales tax added
Markups on cost
Tips on a bill
Interest earned
Rent increases
Population growth
Inventory restocking

Salary raise example

A salary of $62,000 receives a 7% raise: 62,000 × (1 + 7 ÷ 100) = $66,340. The raise itself is 66,340 − 62,000 = $4,340 per year, or about $362 more per month.

Increase a price by a percentage

New Price = Original Price × (1 + Increase Percentage ÷ 100)

For an $80 item whose price rises 15%: 80 × 1.15 = $92, so the price goes up by $12.

Increase by 10%, 20%, 25% and 50%

10% — multiply by 1.10. 450 × 1.10 = 495.
20% — multiply by 1.20. 350 × 1.20 = 420.
25% — multiply by 1.25. 1,200 × 1.25 = 1,500.
50% — add half of it. 600 × 1.50 = 900.

Percentage increase vs. percent change

Increase a number by a percentage: you know the percentage and want the new value. Increase 500 by 20% → 600.

Calculate percentage increase: you know the old and new values and want the percentage. A price rising from 500 to 600 is (600 − 500) ÷ 500 × 100 = 20%.

If you already know both values, use the Percent Change Calculator instead. To go the other way and take a percentage off, use the Decrease by Percentage Calculator.

Frequently asked questions

How do I add a percentage to a number?

Multiply the original number by 1 plus the percentage expressed as a decimal. For example, to add 15% to 200: 200 × (1 + 0.15) = 230.

What is 100 increased by 20%?

20% of 100 is 20, so 100 + 20 = 120.

What is 500 increased by 10%?

500 × 1.10 = 550.

What is 1,000 increased by 25%?

1,000 × 1.25 = 1,250.

How do I calculate a salary increase?

Multiply your current salary by 1 + raise percentage ÷ 100. A 7% raise on $62,000 gives 62,000 × 1.07 = $66,340.

Is increasing by 20% the same as multiplying by 120%?

Yes. Adding 20% leaves you with 120% of the original value, so X × (1 + 20 ÷ 100) is the same as X × 1.20.