Convert a measurement
Metric and US units, converted as you type.
Result
100 centimeters = 39.3701 inches
How it works
Convert between metric and US units
Every conversion here uses the exact internationally agreed factors: an inch is defined as exactly 25.4 millimeters and a pound as exactly 453.59237 grams, so results are precise rather than approximate.
The conversions people reach for most
One inch is 2.54 cm, one foot is 30.48 cm, one mile is about 1.61 km. One kilogram is about 2.2 pounds, and one stone is exactly 14 pounds. Memorizing these five covers most everyday estimates.
Temperature is different
Length and weight scale by multiplication, but temperature scales have different zero points, so the formula has two steps: °F = °C × 9/5 + 32. That is why 0°C is 32°F, not 0°F.
Quick mental math for temperature
Double the Celsius value and add 30 for a fast Fahrenheit estimate. It is exact at 10°C (50°F) and stays within a few degrees across normal weather temperatures.
Rounding
Results are rounded to six decimal places for display. If you are cutting materials or dosing anything by weight, keep the full precision until the final figure and round once at the end.