Percentage Calculator

Choose the calculation type that matches your question:

• Percent Of: Use this when you know a percentage and a total, and want the part. "What is 18% of $64?" Enter 18 and 64, get $11.52. Common for calculating tips, discounts, or commission.
• What Percent: Use this when you know the part and the total, and want the percentage. "30 students passed out of 120 total, what percent passed?" Enter 30 and 120, get 25%. Common for test scores, conversion rates, or market share.
• Percent Change: Use this when comparing two values over time to measure growth or decline. "Revenue went from $45,000 to $52,000, what was the increase?" Enter 45,000 and 52,000, get +15.6%. Direction matters here.
• Percent Difference: Use this when comparing two values without a clear "before" and "after." It uses the average of both values as the base, so the result is the same regardless of which value you enter first. Common in scientific comparisons or price comparisons between two similar products.

Percent of a number:
Answer = (Percentage / 100) × Total
Example: 15% of $200 = (15/100) × 200 = $30

What percent is A of B:
Percent = (Part / Total) × 100
Example: 45 out of 180 = (45/180) × 100 = 25%

Percent change:
Change% = (New - Old) / |Old| × 100
Example: $50 to $65 = (65-50)/50 × 100 = +30%

Percent difference:
Diff% = |A - B| / ((A + B) / 2) × 100
Example: 80 vs 100 = |80-100| / 90 × 100 = 22.2%

Common percentage benchmarks to know: