Percentage Calculator

Percent problems come in three flavors that people constantly mix up: taking a percent of a number, expressing one number as a percent of another, and measuring how much something grew or shrank. This page keeps all three solvers visible at once, so you pick the row that matches your question and type straight into it.

Results update as you type, with increases and decreases clearly signed so a price drop never reads like a gain.

Common uses

• Figure a 15% deposit on a purchase
• Check what fraction of a budget has been spent
• Measure the percent change between last month's and this month's numbers
• Sanity-check a discount or markup someone quoted you

Example

% change from 50 to 75

+50%

Are the numbers I type into this calculator sent to a server?

No. All three solvers run as JavaScript in your browser, so nothing you enter is transmitted or stored — which matters when you're working through salaries, prices, or other financial figures.

How do I calculate the percent change between two numbers?

Subtract the old value from the new one, divide by the old value, and multiply by 100: ((new − old) ÷ old) × 100. Going from 50 to 75 is (25 ÷ 50) × 100 = +50%; a negative result means a decrease.

Why can't I get a percent change starting from zero?

Percent change divides by the starting value, and dividing by zero is undefined — no percentage can describe growth from nothing. The calculator leaves the result blank in that case instead of showing infinity.

What's the difference between a percent change and percentage points?

Percentage points measure the raw gap between two percentages, while percent change measures relative growth. Moving from 5% to 7% is a rise of 2 percentage points but a 40% increase, because 2 is 40% of the starting 5.