Percent change calculator
Runs 100% in your browser. Numbers stay on your device.
Whether you are tracking a price move, a score improvement, or a metric week over week, percent change answers “how much did it move relative to where it started?” TryCalculatingNow runs that formula locally — educational math only.
Quick example
((65 − 50) ÷ 50) × 100 = 30%
A drop from 65 to 50 is −23.08% relative to 65 — always divide by the old value.
How to use it
- Open the calculator (link above prefills Percent change mode).
- Enter starting and ending values.
- Read the signed percent and the plain-language increase/decrease note.
Frequently asked questions
What is the percent change formula?
Percent change = ((new − old) ÷ old) × 100. Positive means an increase; negative means a decrease from the starting value. Division by zero is undefined if old is 0.
Is percent change the same as percent of?
No. “15% of 80” multiplies; percent change compares two amounts relative to the start. Use Percent change mode for from→to; use “What is X% of Y?” for of-mode.
Can I use this for prices or exam scores?
Yes for relative change (50 → 65 is +30%). For marks as a percent of a total, use “X is what % of Y?” instead. For weighted finals, use the Final Grade Calculator.
Are my numbers uploaded?
No. All arithmetic runs in your browser after load. Refresh clears inputs.