# Day Converter URL: https://speedycalculator.com/calculators/conversion/day-converter/ Last updated: 2026-10-25 > The day converter converts time between hours, minutes, seconds, weeks, months, years and more. Choose any “from” and “to” unit, type a number into any field and every other unit updates instantly; all conversion factors are exact definitions. ## Inputs - From (day, s, ms, µs, ns, min, h, week, fortnight, month, year, decade, century, millennium) ## Results - To - Minutes - Seconds - Weeks - Months - Years - As years, months, days ## Formula ``` 1 day = 24 h 1 day = 1,440 min 1 day = 86,400 s 1 day = 0.14285714 week 1 day = 0.032854884 month ``` ## Explanation A day is 24 hours or 86,400 seconds. Converting days to weeks or hours is exact; converting to months and years uses Gregorian averages, because real months and years vary in length. ### How to use the Day Converter - Pick the unit you are starting from in the **From** menu and type your value. - Pick the unit you want in the **To** menu. The heading changes to match – for example “Days to Hours Converter”. - The most common time units are shown below at the same time, so you can compare them at a glance. - Type into any result to convert backwards, then use **Copy results** – the copied text starts with the heading for your chosen units. Results update as you type. Everything is calculated in your browser. ### How it works Every time unit is defined by an exact factor relative to the second (the base unit). The calculator first turns the value you type into seconds, then turns that into the unit you picked in the “To” menu and into each of the common units below it. This two-step method means any unit can be converted to any other – 14 units are available in each menu – and you can type into any field, including a result, to work in the other direction. Changing a unit menu keeps the quantity the same and just re-expresses it, and the page heading and copied results follow your choice. ### How to convert time units - Choose the unit you have in the **From** menu and type the value, for example **30 day**. - Choose the unit you want in the **To** menu, for example hours. The page heading changes to “Days to Hours Converter”. - The calculator multiplies by the second factor of the “from” unit and divides by the factor of the “to” unit: 30 day × 86,400 ÷ 3,600 = **720 h**. ### 1 day in common units UnitValueHours (h)24Minutes (min)1,440Seconds (s)86,400Weeks (week)0.14285714Months (month)0.032854884Years (year)0.002737907 ### Days conversion table Dayshminsweek1241,44086,4000.14285714716810,080604,80013072043,2002,592,0004.2857143902,160129,6007,776,00012.8571431002,400144,0008,640,00014.2857143658,760525,60031,536,00052.1428571,00024,0001,440,00086,400,000142.85714 ### What is a day? A day is 24 hours or 86,400 seconds. Calendar days occasionally differ by one second when a leap second is added. ### What is an hour? An hour is 60 minutes or 3,600 seconds. Wages, shifts and travel times are counted in hours. ### What is a minute? A minute is 60 seconds. The base-60 split of hours and minutes comes from ancient Babylonian astronomy. ### Common mistakes to avoid Treating every month as 30 days or every year as 365 days in long calculations, and writing decimal hours such as 1.5 h as 1 h 50 min (it is 1 h 30 min). ## Worked example Inputs — From: 30 day. Results — **To = 720 h**; Minutes = 43,200 min; Seconds = 2,592,000 s; Weeks = 4.28571429 week; Months = 0.98564652 month; Years = 0.08213721 year; As years, months, days = 7096 y 7 m 26 d. ## FAQ **How many hours in 30 days?** 720 hours. **How many weeks in a year?** About 52.18 weeks. **Why does a year here have 365.2425 days?** That is the average Gregorian year including leap years. **How do I change the units?** Pick any unit in the From and To menus. The value is converted in place, and the heading changes to show your conversion, for example “Days to Hours Converter”. **Can I type into any field?** Yes. Every field is editable, so you can start from whichever unit you have. **How many units can I convert between?** 14 time units, from the everyday to the specialised. **Which units are exact?** All factors here are exact by definition except astronomical and similar reference values, which use internationally agreed constants. **What formula does the Day Converter use?** 1 day = 24 h. ## Sources - [NIST Special Publication 811 – Guide for the Use of the International System of Units](https://www.nist.gov/pml/special-publication-811) - [NIST Handbook 44 Appendix C – General tables of units of measurement](https://www.nist.gov/pml/owm/nist-handbook-44-current-edition)