Convert a duration (seconds, minutes, hours, days)

The input is converted into seconds, then into the target unit. Every factor is exact: a minute is 60 seconds, an hour 3,600, a day 86,400 and a week 604,800. A month has no fixed length and a civil year alternates between 365 and 366 days, so those belong to date arithmetic, not to a linear conversion.

t(s) = x × kfrom ; y = t(s) / kto

1 h = 3600 s ; 1 day = 86,400 s

1 week = 7 × 86,400 = 604,800 s

The second is the SI unit of time, defined by the hyperfine transition of caesium-133. The usual multiples — minute, hour, day — are not SI units but their use is accepted. The 86,400-second civil day ignores leap seconds, which are rare and decided case by case.

Value

The duration alone, without the unit. A decimal result such as 1.5 h reads as 1 h 30.

From

Starting unit. The default is the minute.

To

Target unit. The default is the hour.

Assumptions

• 1 day = 86,400 seconds, with no leap second.
• 1 week = 7 days exactly.
• Months and years are excluded because their length varies.

Limits

• No conversion into months or years: use date arithmetic instead.
• Leap seconds and daylight-saving changes are not taken into account.
• A decimal result is not a clock reading: 1.75 h is 1 h 45, not 1 h 75.

1.5 hours means an hour and a half, so 1 h 30. The classic slip is reading the decimal part as minutes: 1.75 h is 1 h 45 because 0.75 × 60 = 45. To add up working hours, convert everything into minutes, add, then go back to hours.

• Reading 2.5 h as 2 h 50.

  0.5 of an hour is 30 minutes: 2.5 h = 2 h 30.

• Converting a duration into months with a fixed factor.

  A month lasts 28 to 31 days; use date arithmetic.

• Ignoring the clock change on a duration crossing March or October.

  That day has 23 or 25 hours; this converter assumes 24.

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Written by Rédaction HexaCalc (editorial team). Content last updated: August 25, 2026. No third-party medical or financial review is claimed.

• NIST Guide to the SI, Appendix B: Conversion Factors — National Institute of Standards and Technology
• The International System of Units (SI) — Bureau international des poids et mesures (BIPM)