Rounding & Significant Figures Calculator
Round a number to any decimal place or number of significant figures — half up, half even (banker's), always up or always down — and count its sig figs.
How to use
- 1Enter a number and choose decimal places or significant figures.
- 2Pick the rounding rule.
How it's calculated
Half up rounds 0.5 away from zero; half even (banker's rounding) rounds 0.5 to the nearest even digit. Sig-fig counting: leading zeros never count; trailing zeros count only after a decimal point.
Frequently asked questions
How many significant figures does 0.00520 have?
Three — the leading zeros don't count, but the trailing zero after the decimal point does.
What is banker's rounding?
Rounding exact halves to the nearest even number (2.5 → 2, 3.5 → 4), which avoids an upward bias in sums. It's the IEEE 754 default.
How do I round to the nearest ten or hundred?
Use negative decimal places: −1 rounds to the nearest 10, −2 to the nearest 100.