Prime Calc
Smart everyday calculators
Percentages

Everyday percentage calculations in one clean page.

This page combines the most useful percentage tools into a single section: percentage of a number, reverse percentage, increase, decrease, change, and ratio-to-percent calculations. It uses the same design system as the rest of the site.

Live tools
6 Calculators
Good for
Prices, discounts, growth
Next expansion
Markup & margin

Percentage Tools

Each calculator updates instantly as values change, so the page feels fast and useful without extra clicks.

What is X% of Y?

Find a percentage of a given value.

Result
0.00

X is what percent of Y?

Convert part-versus-whole into a percentage.

Result
0.00%

Percentage Increase

Apply a percentage increase to an original number.

New value
0.00

Percentage Decrease

Apply a percentage decrease to an original number.

New value
0.00

Percentage Change

Measure the change from one value to another as a percentage.

Percentage change
0.00%

Reverse Percentage

Work backwards from a final value after an increase or decrease.

Original value
0.00