Calculators & Converters

Percentage calculator

Pick the question you are asking, type two numbers and get the answer with the working shown, so you can check it or copy it into a sheet.

Free, no sign-up
Runs in your browser
Nothing uploaded

Question

What do you want to work out?

Numbers

Percentage (X)

Of this number (Y)

This number (X)

Is what percent of this (Y)

Starting value (X)

New value (Y)

Number (Y)

Add this percentage (X)

Number (Y)

Subtract this percentage (X)

This number (Y)

Is this percentage (X) of the whole

First number (X)

Second number (Y)

Final price

For example a price that already includes GST.

After this percentage was added

Result

How it works

Percent means "per hundred". Every percentage question is one of a few shapes, so the calculator asks which one you mean and fills in the formula.

X% of Y = X × Y ÷ 100
X is what % of Y = X ÷ Y × 100
% change = (new − old) ÷ |old| × 100
Add X% = Y × (1 + X/100), subtract X% = Y × (1 − X/100)
Whole = part ÷ (X/100)
% difference = |X − Y| ÷ average(X, Y) × 100

Percentage change and percentage difference are different questions. Change has a direction and uses the old value as the base. Difference is symmetric and compares two values with neither as the base.

Frequently asked questions

How do I take GST out of a price?

Use the last mode, "find the original": enter the final price and the GST rate. Dividing by 1.18 is not the same as subtracting 18%.

Why is adding 20% then removing 20% not back to the start?

The second 20% is taken from a bigger number. 100 + 20% = 120, and 120 − 20% = 96.

Is anything sent anywhere?

No. It is all calculated in your browser.