🔢 Number Tools

Free calculators and converters for everyday number problems. All run instantly in your browser.

Calculate percentages instantly — find X% of Y, what percentage X is of Y, percentage increase/decrease, and reverse percentages.

Convert numbers to Roman numerals or Roman numerals to numbers. Supports 1 to 3999. Shows a full symbol breakdown.

Generate random numbers within any range. Single or bulk. Unique numbers, no repeats mode. Includes a dice roller with D4 through D100.

Find missing image dimensions from a ratio, or calculate the aspect ratio from width and height. Common ratio presets included.

Convert numbers between decimal, binary, hexadecimal and octal. All four bases shown simultaneously with a reference table.

Calculate the tip on any bill and split it between any number of people. Tip slider, preset buttons, per-person breakdown.