Significant figures calculator and rounder

How to use this tool

1. Enter your values or choose a local file. Replace the example data with your own.
2. Review options, units and assumptions, then run the tool.
3. Check the result before copying or downloading it. Keep an original copy of important files.

Method & assumptions

Count significant figures in any number and round it to the number of sig figs you need, with scientific notation.

Worked example

Number: 0.0045060
Round to … significant figures (0 = no rounding): 3

→ Significant figures: 5
→ Significant digits: 4 5 0 6 0
→ Scientific notation: 4.5060 × 10⁻³
→ Rounded to 3 significant figures: 0.00451
→ Rounded, in scientific notation: 4.51 × 10⁻³

Limits & important notes

Basic release. Review the result before relying on it. File limits, supported cases and processing requirements are shown above.

Content updated: 2026-10-10