Conversion method
Here a day is exactly 24 hours and a week exactly seven days. Months and years use the Gregorian average of 365.2425 days per year; they do not represent a particular calendar interval or daylight-saving transition.
min = x × 60
10 h = 600 min.
| h | min |
|---|---|
| 1 | 60 |
| 5 | 300 |
| 10 | 600 |
| 25 | 1500 |
| 50 | 3000 |
| 100 | 6000 |
Unit definitions and sources
Days mean 24 hours. Average years and months use the Gregorian 400-year average; they do not calculate elapsed calendar dates or leap seconds.
13 of the 23 definitions below were checked against the cited sources on 2026-09-20 (AI-assisted check).
| Unit and system | Use | Definition | Relationship |
|---|---|---|---|
| Millisecond (ms); si | Common units | Millisecond measures time. s = (value in ms) × 0.001. Common use: Elapsed durations. | Exact definition; numerical display may be rounded |
| Second (s); si | Common units | Second measures time. s = (value in s) × 1. Common use: Elapsed durations. | Exact definition; numerical display may be rounded |
| Minute (min); si | Common units | Minute measures time. s = (value in min) × 60. Common use: Elapsed durations. | Exact definition; numerical display may be rounded |
| Hour (h); si | Common units | Hour measures time. s = (value in h) × 3600. Common use: Elapsed durations. | Exact definition; numerical display may be rounded |
| Day (d); si | Common units | Day measures time. s = (value in d) × 86400. Common use: Elapsed durations. | Exact definition; numerical display may be rounded |
| Week (wk); other | Common units | Week measures time. s = (value in wk) × 604800. Common use: Elapsed durations. | Exact definition; numerical display may be rounded |
| Month (average) (mo); other | Common units | Month (average) measures time. s = (value in mo) × 2629746. Common use: Elapsed durations. 365.2425 days ÷ 12 | Approximate / conventional |
| Year (average) (yr); other | Common units | Year (average) measures time. s = (value in yr) × 31556952. Common use: Elapsed durations. 365.2425 days | Approximate / conventional |
| Nanosecond (ns); si | Specialist units | Nanosecond measures time. s = (value in ns) × 1e-9. Common use: Elapsed durations. | Exact definition; numerical display may be rounded |
| Microsecond (µs); si | Specialist units | Microsecond measures time. s = (value in µs) × 0.000001. Common use: Elapsed durations. | Exact definition; numerical display may be rounded |
| Exasecond (Es); si | Specialist units | exasecond: E denotes 10^18; the unit gives 1000000000000000000 s. Common use: Elapsed durations. | Exact definition; numerical display may be rounded |
| Petasecond (Ps); si | Specialist units | petasecond: P denotes 10^15; the unit gives 1000000000000000 s. Common use: Elapsed durations. | Exact definition; numerical display may be rounded |
| Terasecond (Ts); si | Specialist units | terasecond: T denotes 10^12; the unit gives 1000000000000 s. Common use: Elapsed durations. | Exact definition; numerical display may be rounded |
| Gigasecond (Gs); si | Specialist units | gigasecond: G denotes 10^9; the unit gives 1000000000 s. Common use: Elapsed durations. | Exact definition; numerical display may be rounded |
| Megasecond (Ms); si | Specialist units | megasecond: M denotes 10^6; the unit gives 1000000 s. Common use: Elapsed durations. | Exact definition; numerical display may be rounded |
| Kilosecond (ks); si | Specialist units | kilosecond: k denotes 10^3; the unit gives 1000 s. Common use: Elapsed durations. | Exact definition; numerical display may be rounded |
| Hectosecond (hs); si | Specialist units | hectosecond: h denotes 10^2; the unit gives 100 s. Common use: Elapsed durations. | Exact definition; numerical display may be rounded |
| Decasecond (das); si | Specialist units | decasecond: da denotes 10^1; the unit gives 10 s. Common use: Elapsed durations. | Exact definition; numerical display may be rounded |
| Decisecond (ds); si | Specialist units | decisecond: d denotes 10^-1; the unit gives 0.1 s. Common use: Elapsed durations. | Exact definition; numerical display may be rounded |
| Centisecond (cs); si | Specialist units | centisecond: c denotes 10^-2; the unit gives 0.01 s. Common use: Elapsed durations. | Exact definition; numerical display may be rounded |
| Picosecond (ps); si | Specialist units | picosecond: p denotes 10^-12; the unit gives 1e-12 s. Common use: Elapsed durations. | Exact definition; numerical display may be rounded |
| Femtosecond (fs); si | Specialist units | femtosecond: f denotes 10^-15; the unit gives 1e-15 s. Common use: Elapsed durations. | Exact definition; numerical display may be rounded |
| Attosecond (as); si | Specialist units | attosecond: a denotes 10^-18; the unit gives 1e-18 s. Common use: Elapsed durations. | Exact definition; numerical display may be rounded |
Sources: BIPM: International System of Units; NIST: SP 811 Appendix B.8: conversion factors; US Naval Observatory: Leap years and the Gregorian calendar; BIPM: SI prefixes
Precision of time conversions
All 23 time units convert through Second (s). 21 have an exact defined relationship to the base unit and 2 are conventional or measured values. Results and the tables on this page come from the same engine, so a table value can be checked against the converter directly.
Standard display shows up to six decimal places, switching to scientific notation for very large or small values. Calculation uses JavaScript binary floating point independently of display rounding, so extra digits are not a claim about measurement accuracy. Each unit lists its own source; a citation records where the definition comes from, not an independent review. See Conversion methodology for the review and correction process.