How do you calculate a percentage increase on a value?

New value = original × (1 + percent/100), or original + (percent/100 × original). 100 increased by 15% = 115.

Is percentage increase the same as percentage change?

Percentage increase on a value adds a percent to a number. Percentage change compares two values (from A to B).

Does this include tax on a salary?

No. The result is the same kind of number you typed. A gross salary in, a gross salary out. Take-home pay depends on brackets and contributions this tool does not model.

Can I increase by more than 100%?

Yes. A 150% increase multiplies by 2.5. You keep the original and add one and a half times it. That is different from “150% of” the original, which multiplies by 1.5.

Can I model two raises in a row?

Run the first raise, then type the new total as the next starting value. Or multiply the factors yourself: a 3% raise and then a 5% raise is 1.03 × 1.05 = 1.0815, an 8.15% increase on the original, not 8%.

What about a raise that is “2 percentage points”?

If a rate moves from 5% to 7%, the gap is 2 percentage points, or a 40% relative increase of the rate itself (2 / 5). Typing 5 and increasing by 2% produces 5.1, which is neither of those. Read the noun. This page increases the number in the first box.

Does a negative percent work?

A negative rate on Increase flips the sign and behaves like a decrease. Prefer the Decrease direction so the formula line matches the sentence. A positive rate with Decrease selected is the readable version of the same math.

Percentage Increase Calculator

Increase a starting value by any percentage. Use it for markups, salary raises, growth projections, and “plus X%” problems.

Written and maintained by Ricardo Rodrigues · Last updated October 7, 2026 · What changed

Who this calculator is for

This page is for a rate you already know and a starting amount you want to grow. A salary offer, a price “plus 8%,” a population projection in a textbook, a fee that increases by a stated percent. The output is the new amount and the size of the piece that was added. The page opens with Increase selected. Decrease is the other button in the same mode, and it is a different operation.

If you have last year’s number and this year’s number and you want the percent, you do not have a rate yet. That is percentage change. If you have a rate and you want only the piece, not the new total, that is percent-of. People mix those three up most often on pay and on prices.

Percentage Increase / Decrease

Increase or decrease a value by a percentage

Starting value

By percentage

Direction

Quick select

Result

Enter values to calculate

Comparison table

A rise and a fall of the same percent do not cancel
Change	100 after rise	Then fall by same %	Net change	Fall needed to undo rise
10%	110	99	-1%	9.09%
20%	120	96	-4%	16.67%
25%	125	93.75	-6.25%	20%
50%	150	75	-25%	33.33%
75%	175	43.75	-56.25%	42.86%

About this percentage increase

An increase calculator applies a rate you already know. New value = old × (1 + rate/100). A €40,000 salary raised by 4% becomes €41,600. The raise itself is €1,600, which is the rate times the old salary — not times the new one.

It will not discover the rate from two salaries. If you have both numbers and want the percent, use percentage change. It will also not tell you whether 4% beat inflation; that is a second percent you subtract or, more carefully, divide as factors.

How to use each field

Starting value: The base the percent sticks to. A €40,000 salary goes here, not the hoped-for new salary. The rate is applied to this box. Type the units you want back: gross stays gross, a headcount stays a headcount.
By percentage: The rate, already decided. 4 means multiply by 1.04. Decimals are allowed. A rate over 100 is allowed and means you add more than the original itself. Quick-select overwrites this box.
Direction: Increase adds the piece. Decrease subtracts it. This URL opens on Increase. If you tap Decrease, you are using the decrease formula; the dedicated decrease page explains the ways that formula gets misread on sale tags.
The two numbers in the result: The large number is the new value. The signed amount beside it is only the piece that was added. 40,000 increased by 4% shows 41,600 and +1,600. Copy the one your sentence needs. A contract that says “the new salary” wants 41,600. A sentence about “the raise” wants 1,600.

When to use this calculator

HR, a contract, or a homework problem gives you the percent and the starting amount.
You are comparing 3%, 5%, and 8% on the same base before you negotiate.
You want the euro amount of the raise separated from the new total.

Worked examples

Example calculations for Percentage Increase
Question	Answer
100 increased by 15%	115
80 increased by 25%	100
50 increased by 10%	55

Walkthroughs

A 4% salary increase, gross, one year

Starting value 40000, by percentage 4, direction Increase. New gross is 41,600. The raise is 1,600. Nothing on the page withheld tax, social contributions, or a bonus. If the offer says “4% on base, bonus separate,” do not put the bonus in the starting value and then also talk about it as extra.

To recover the old salary from the new one, divide by 1.04: 41,600 / 1.04 = 40,000. Subtracting 4% of 41,600 lands on 39,936, which is the classic wrong undo. The increase page applies a rate. It does not search for the rate that would get you home.

A supplier price that rises 12.5%

A part costs €64 before the increase. Starting value 64, by percentage 12.5. The new price is 72. Ten percent is 6.40, 2.5% is 1.60, and the sum is 8, so 64 + 8 = 72. If the supplier’s email says “from 64 to 72,” check it on the change calculator: (72 − 64) / 64 = 12.5%. The match means the email and the rate are the same fact.

Formula

Goal	Formula
Value after increase	value × (1 + percent/100)

New value = starting value × (1 + percent ÷ 100). The piece alone is starting value × (percent ÷ 100). Adding them returns the new value, which is a useful checksum. 40,000 × 0.04 = 1,600, and 40,000 + 1,600 = 41,600, and 40,000 × 1.04 = 41,600.

The base does not move. A second 4% raise, a year later, applies to 41,600, not to 40,000, and it is worth 1,664. Two successive 4% increases are not an 8% increase on the original. They compound: 1.04 × 1.04 = 1.0816, an 8.16% increase on the first base. This page applies one rate to one base per calculation. Run it again if there is a second year.

Inflation is a second percent, not a mood. A 4% raise against 3% inflation is not automatically a 1% gain in purchasing power, though subtracting the rates is the usual shorthand. The more careful comparison divides the factors: 1.04 / 1.03 ≈ 1.0097, about 0.97% more purchasing power. The inflation guide shows when the shorthand is close enough and when it is not. This calculator will not subtract a second rate unless you type the problem that way yourself.

Mistakes this page will not catch for you

Applying the raise to the new salary

Four percent of €41,600 is €1,664, which is not the raise that produced €41,600 from €40,000. The rate sticks to the old base. Reverse the operation by dividing the new salary by 1.04 if you need the old one.

Treating a percentage-point move as this tool’s input

A rate that goes from 2% to 3% is not “increase 2 by 1%.” It is either +1 percentage point or a 50% relative increase of the rate. Type 2 only if you truly mean “make the number 2 one percent larger,” which yields 2.02.

Putting the percent in the starting-value box

A sentence like “increase 4 by 100%” is a tiny number becoming 8. It is not a 4% raise. The rate belongs in By percentage. The amount belongs in Starting value. The boxes are labeled that way because swapping them is an easy way to grow the wrong thing.

FAQ

How do you calculate a percentage increase on a value?: New value = original × (1 + percent/100), or original + (percent/100 × original). 100 increased by 15% = 115.
Is percentage increase the same as percentage change?: Percentage increase on a value adds a percent to a number. Percentage change compares two values (from A to B).
Does this include tax on a salary?: No. The result is the same kind of number you typed. A gross salary in, a gross salary out. Take-home pay depends on brackets and contributions this tool does not model.
Can I increase by more than 100%?: Yes. A 150% increase multiplies by 2.5. You keep the original and add one and a half times it. That is different from “150% of” the original, which multiplies by 1.5.
Can I model two raises in a row?: Run the first raise, then type the new total as the next starting value. Or multiply the factors yourself: a 3% raise and then a 5% raise is 1.03 × 1.05 = 1.0815, an 8.15% increase on the original, not 8%.
What about a raise that is “2 percentage points”?: If a rate moves from 5% to 7%, the gap is 2 percentage points, or a 40% relative increase of the rate itself (2 / 5). Typing 5 and increasing by 2% produces 5.1, which is neither of those. Read the noun. This page increases the number in the first box.
Does a negative percent work?: A negative rate on Increase flips the sign and behaves like a decrease. Prefer the Decrease direction so the formula line matches the sentence. A positive rate with Decrease selected is the readable version of the same math.