How does rounding to sig figs work?

Keep the first N significant digits and round the rest. Example: 0.00456 to 2 sig figs → 0.0046.

What if the number is very large?

The result may be in scientific notation (e.g. 12345 to 2 sig figs → 12000 or 1.2×10⁴).

Yes. Valid range is typically 1–20 significant figures.

Round a number to a specified number of significant figures.

Number

Significant figures

How does rounding to sig figs work?: Keep the first N significant digits and round the rest. Example: 0.00456 to 2 sig figs → 0.0046.
What if the number is very large?: The result may be in scientific notation (e.g. 12345 to 2 sig figs → 12000 or 1.2×10⁴).
Can I round to 1 sig fig?: Yes. Valid range is typically 1–20 significant figures.

Celsius to Fahrenheit Converter

Convert Celsius to Fahrenheit and Fahrenheit to Celsius instantly. Free temperature converter.

Tip Calculator

Calculate tip and split the bill. Enter bill amount, tip percentage, and number of people.

Roman Numeral Converter

Convert numbers to Roman numerals and Roman numerals to numbers. Supports 1–3999.

Combinations Calculator

Calculate C(n,r) — the number of ways to choose r items from n without order. Uses n!/(r!(n-r)!).

Combinations with Replacement Calculator

Calculate the number of ways to choose r items from n with repetition allowed. Formula: C(n+r-1, r).

Even Permutations Calculator

Count how many permutations of n objects are even (expressible as an even number of swaps). For n ≥ 2, equals n!/2.