OmniTools

Percentage Calculator

Calculate percentage values, percentage changes, ratios, and increases.

Basis: Standard definitions of ratio, percentage change and percentage point·2026-08-28 verified·Editorial policy

Before you rely on this

Percentage increases and decreases do not cancel — 100 raised by 10% is 110, and lowering that by 10% gives 99, not 100. Percent and percentage point also differ: a move from 3% to 5% is a rise of 2 percentage points, not 2 percent.

Tool Overview & Key Purpose

Calculate percentage of a number, percentage change/increase/decrease, and relative ratios.

Step-by-Step Usage Instructions

1STEP 1

Select percentage calculation mode (% of total, % change, ratio, or inverse %).

2STEP 2

Input values A and B.

3STEP 3

Instantly view calculated percentage, difference, and change ratio.

4STEP 4

Copy output values with a single click.

Real-World Scenarios & Practical Cases

3 Practical CasesScenario #1

Stock Market Gain & Loss Percentage

Buying stock at $50 and selling at $62.50 yields a +25.0% return on investment.

Calculate exact price movements easily.Scenario #2

Year-over-Year Revenue Growth

Revenue expanding from $120,000 to $150,000 translates to a +25% YoY growth rate.

Perfect for business reporting and pitch decks.Scenario #3

Test Score & Target Goal Completion

Answering 68 out of 85 exam questions correctly equals an 80.0% score.

Instantly measure test performance metrics.Percentage formulasPercentage Change = [(Final - Initial) / |Initial|] × 100 (%)

Pro Tips & Key Considerations

Recovering from a 50% loss requires a 100% gain, not a 50% gain.Percentage points (%p) measure arithmetic difference between two percentages.

Frequently Asked Questions (FAQ)

Sources & References

Khan Academy — Percent Word Problems Math Is Fun — Percentage Reference

Basis: Standard definitions of ratio, percentage change and percentage point · 2026-08-28 verified