Jan. 17, 2021

Time unit converter

Convert time values, calculate averages for seconds, hour, year other metric, scientific and historical units.

Conversion calculator

Enter numeric expression or value, with choice of units. Convert metric to multiple units simultaneously. Adjust precision or fractional display format.

Converted values table:

day1.1574e-5 d
hour2.7778e-4 hr
millisecond1,000 ms
minute0.01667 min
month (30d)3.858e-7 mo
second1 s
week (7d)1.6534e-6 wk
year (365d)3.171e-8 yr
year julian (365.25d)3.1688e-8 yr
femtosecond1.0e+15 fs
microsecond1.0e+6 µs
millisecond1,000 ms
nanosecond1.0e+9 ns
picosecond1.0e+12 ps
second1 s
Astronomical, Scientific
atomic unit of time4.134e+16 au
Earth orbital period3.1688e-8 yr
Martian day1.1264e-5


Control the number of decimal places using precision adjustments. Precison range is 0 to 20, with default = 4. Higher precision values will provide more accurate decimal values.

Fraction denominator

Results in systems marked with # will report values as a fraction. The most popular one being 16 used in Imperial and US Customary measurements. Change this to 32 for 1/32th or 64 for 1/64th marks to be reported.

Expressions or values as input

Numeric expressions evaluated into values

Conversion calculator accepts simple numeric expressions and formulae, that are evaluated internally into decimal numbers. Numeric values like integers, decimals, and scientific notation are also accepted.This is the only unit converter available online that meets this standard.

Why provide support for evaluating expressions in calculations?

This unit converter is designed to meet real world needs. Consider you are in a hardware store with a 5 foot board. You need to cut it into 6 equal pieces and the store needs the size of a single piece in meters or centimeters. This unit converter will accept an expression 5/6 in feet, and compute the fractional value for you without further headaches. It will then express this value in multiple unit systems of your choosing. This simple example shows the flexibility of allowing mathematical expressions as numeric inputs.

Currently mathematical operators +, -, *, /, and use of brackets ( ) are supported. Examples of usage of expressions and numbers are listed below.

Examples of expressions and numeric input values

Mixed fractions2 3/4 or 11/4
Complex fractions4.5/8.1
Simple expressions2/3 * (1 + 1/2) which reduces to 1
Complex expressions2.1 * (4/5 + 8/7)/(3 * (0.5 + 122/455))

Providing values for multi-unit systems

A single unit metric only requires one value. Measurement systems with multiple units can be used as groups like (yard, foot, inch). These require three values to be provided, one for each sub-unit. In such cases provide individual expressions or values with a comma (,) separation. For a (foot, inch) system the input can be 3.5, 1/16 which will be translated as foot=3 and inch=9/16. This feature does not show up in every measure. Length, area, volume, mass and time have multi-unit options.