Days to Hours Converter

About the d to h calculation

One day is exactly 24 hours, so converting between them is a single multiplication. Enter any value above and the result updates as you type. Twenty-four hours, or 86,400 seconds — one full rotation of the Earth relative to the Sun. Sixty minutes, or 3,600 seconds. The basis of timekeeping and of most pay calculations.

Formula

h = d × 24

1 d = 24 h
1 h = 0.041667 d

Worked example

To convert 30 d, multiply by 24: 30 × 24 = 720 h.

Frequently asked questions

How many hours are in a day?

There are 24 hours in one day. To convert any amount, multiply the number of days by 24.

How do I convert hours back to days?

Divide instead of multiplying, or equivalently multiply by 0.041667. One hour is 0.041667 days.

Is this conversion exact?

For seconds through weeks, yes — they are fixed multiples. The year is the mean Gregorian year of 365.2425 days, which is an average rather than the length of any particular calendar year.

Where is each of these units used?

Days: twenty-four hours, or 86,400 seconds — one full rotation of the Earth relative to the Sun. Hours: sixty minutes, or 3,600 seconds. The basis of timekeeping and of most pay calculations.

Sources

• NIST Special Publication 811 — Guide for the Use of the International System of Units