Day to Hour (d to h)
Result
24 Hour
Formula
h = d × 24
1 d = 24 h, and 1 h = 0.04166666667 d.
The second is the SI base unit, defined by a caesium-133 transition frequency. Minutes, hours, days and weeks are exact multiples. Month and year here are Gregorian averages: a year of 365.2425 days and a month of one twelfth of that (30.436875 days).
Worked examples
- 1 d × 24 = 24 h
- 10 d × 24 = 240 h
- 100 d × 24 = 2,400 h
Common mistakes
- Calendar months run from 28 to 31 days, so "3 months" from a given date is not 3 × 30.44 days. Use a date calculator for deadlines.
- A 365-day year, a 365.25-day Julian year and the 365.2425-day Gregorian year differ; interest and astronomy calculations specify which one they use.
Day to Hour table
| Day (d) | Hour (h) |
|---|---|
| 1 | 24 |
| 2 | 48 |
| 5 | 120 |
| 10 | 240 |
| 20 | 480 |
| 50 | 1,200 |
| 100 | 2,400 |
| 1,000 | 24,000 |
The units
- Day (d)
- 1 Day = 86,400 Second.
- Hour (h)
- 1 Hour = 3,600 Second.
Sources for these factors
- The International System of Units (SI Brochure), 9th edition — BIPM
- Guide for the Use of the International System of Units (SP 811), Appendix B: conversion factors — NIST
Last reviewed against these sources. An automated check recomputes every factor from its definition on each build. How we check accuracy