Hours calculator

Use this hours calculator: type times like 7:30 + 8:15 − 0:45 (= 15:00, or 15.00 decimal hours) or convert between decimal hours and hours:minutes – the result appears instantly, even past 24 hours.

Source: BIPM – SI Brochure: non-SI units accepted for use with the SI (minute, hour, day). Updated: 5 October 2026.

What do you want to calculate?

Calculation

Join with + and −. Allowed: 7:30, 7:30:15 (with seconds), 7.5 (decimal hours), 45m, 1h 30m. A line break or ; counts as +.

My ToolboxYour inputs are saved in this browser only.

Result

Result: 15:00 h
Day: –
Decimal hours: 15
Total minutes: 900
Exact (h:mm:ss): –
In days and hours: –
Pay (hours × hourly rate): –
Overview per line

How it is calculated

How the hours calculator works

Adding hours: every entry is converted to minutes, added up and shown again as hours:minutes. Example: 7:30 + 8:15 − 0:45 = 450 + 495 − 45 = 900 minutes = 15:00 h = 15.00 decimal hours. Totals above 24 hours stay in hours (40:00 h) and are also shown in days (1 day 16:00 h). Mixed notations work in the same calculation, e.g. 7:30 + 45m − 0.5.

Decimal hours conversion

An hour has 60 minutes, not 100, so decimal hours = hours + minutes ÷ 60. 7:45 becomes 7 + 45 ÷ 60 = 7.75 h; 7.75 h = 7 h + 0.75 × 60 min = 7:45. Payroll and timesheet software use decimal hours because they multiply directly by the hourly rate: 7.75 × $20 = $155 — no separate conversion table needed, just divide the minutes by 60.

Minutes to decimal hours (rounded to two places, as on timesheets):

Minutes	Decimal hours	Minutes	Decimal hours
1 min	0.02 h	13 min	0.22 h
2 min	0.03 h	14 min	0.23 h
3 min	0.05 h	15 min	0.25 h
4 min	0.07 h	20 min	0.33 h
5 min	0.08 h	25 min	0.42 h
6 min	0.10 h	30 min	0.50 h
7 min	0.12 h	35 min	0.58 h
8 min	0.13 h	40 min	0.67 h
9 min	0.15 h	45 min	0.75 h
10 min	0.17 h	50 min	0.83 h
11 min	0.18 h	55 min	0.92 h
12 min	0.20 h	60 min	1.00 h

Rounding each line and then adding can be off by a few minutes per month. It is more accurate to add all minutes first and convert once – which is what this calculator does.

Clock time plus duration

22:30 + 3:45 = 26:15, i.e. 02:15 on the next day. Daylight saving changes and calendar dates are not taken into account – for a duration between two specific dates and times (including DST and leap years), use the time calculator instead.

Hours calculator vs. work hours calculator vs. payroll calculator

Tool	Input	Typical question
Hours calculator (this tool)	Durations you already have (7:30, 8:15, 45m)	What is 7:30 + 8:15 − 0:45 in total? What is 7.75 h as hours:minutes?
Work hours calculator	Start time, end time, break	How many hours between 7:30 and 4:15 pm minus a break?
Payroll / hourly wage calculator	Hours × hourly rate	What is the gross pay for 7.75 h at $20/hour?

These three are often searched interchangeably but calculate different things. To go from a start and end clock time, use the work hours calculator; to turn hours into a dollar amount, use a payroll calculator. This hours calculator adds and converts durations that are already known – exactly what payroll clerks call working with decimal or "industrial" minutes.

Hours between two times – with breaks and pay

Choose “From–to times with break” to calculate the hours between a start and an end time. Write one line per day or shift: start, end and then the break in minutes, for example 8:00 - 16:30 30. am/pm works too (9am - 5:30pm 30), and an end time before the start counts as the next day (22:00 to 6:00). The three example lines give 8:00, 8:30 and 7:15 hours, in total 23:45 h = 23.75 decimal hours; at an hourly rate of 20 that is 475.00. You can save the table as CSV or print it, and your lines are part of the page link. For a fixed Monday-to-Sunday week with a weekly target, use the work hours calculator; for a printable sheet for a whole month there is the timesheet template.

Rounding to the quarter hour

Many time clocks round punches to the nearest 15 minutes: 1–7 minutes past a quarter go down, 8–14 minutes go up, so 8:07 becomes 8:00 and 8:08 becomes 8:15. In the US, rounding to the nearest 5 minutes, tenth or quarter of an hour is accepted only if, over time, employees are paid for all the time they actually worked (29 CFR 785.48(b)). This calculator does not round – it adds the exact minutes. To spread many hours over days, use hours to days.

Adding hours past 24 in Excel

Adding times in Excel or Google Sheets often gives a wrong result above 24 hours (e.g. "16:00" instead of "40:00"), because the default time format wraps back to 0 after 24 hours. Fix: set the cell format to [hh]:mm instead of hh:mm – the square brackets stop the wraparound. This calculator shows totals past 24 hours correctly by default, plus a days-and-hours breakdown.

Frequently asked questions

How do I convert minutes to decimal hours?

Divide the minutes by 60: 45 minutes = 0.75 hours, 20 minutes = 0.33 hours. So 8 hours 20 minutes are 8.33 decimal hours.

What is 7.5 hours in hours and minutes?

7 hours and 0.5 × 60 = 30 minutes, i.e. 7:30. Likewise 7.25 h = 7:15, 7.75 h = 7:45, 8.1 h = 8:06.

Why is 7:30 not the same as 7.30 hours?

7:30 means 7 hours 30 minutes = 7.5 decimal hours, whereas 7.30 decimal hours are only 7 hours 18 minutes – the most common timesheet mistake.

Can I add more than 24 hours?

Yes. The result stays in hours (e.g. 168:30 h for a month) and is additionally shown in days and hours.

Can I enter seconds?

Yes, as h:mm:ss, e.g. 0:03:45. If the result contains seconds it is shown as h:mm:ss.

Can I use this as a payroll hours calculator?

Yes. Add up clocked-in times (e.g. 7:30 + 8:15 − 0:45) and read off the decimal hours – the format payroll software and timesheets need, since it multiplies directly by the hourly rate.

What are decimal or "industrial" minutes?

Payroll teams sometimes call decimal hours "industrial minutes": instead of leaving a duration as hours and minutes, the minutes are divided by 60. Converting industrial minutes means turning 7:45 into 7.75 h – exactly what the "hours:minutes → decimal hours" mode does.

Hours calculator vs. hourly wage calculator – what is the difference?

This hours calculator adds, subtracts and converts durations (e.g. 7:30 + 8:15, or 7.75 h → 7:45). An hourly wage / payroll calculator multiplies hours by a pay rate to get gross or net pay. Use this tool first to get the total hours, then a wage calculator for the dollar amount.

How do I add hours and minutes?

Convert everything to minutes, add, then convert back: 7:30 + 8:15 = 450 + 495 = 945 minutes = 15:45. If the minutes exceed 60, carry the extra hour – 0:45 + 0:30 = 1:15. Type the times joined by + above and the calculator does this for you. For start and end times, choose the mode “From–to times with break”.

Why does adding hours in Excel give the wrong result past 24 hours?

Because the default time format wraps back to 0 after 24 hours. Fix in Excel/Sheets: change the cell format to [hh]:mm. This calculator has no such formatting trap and shows totals past 24 hours correctly, plus a days breakdown.

How do I round time to the nearest quarter hour?

Look at the minutes past the last quarter: 1–7 minutes round down, 8–14 round up. 7:52 becomes 7:45 (7 minutes past), 7:53 becomes 8:00 (8 minutes past). In decimal hours a quarter is 0.25.

Sources and legal basis

BIPM – SI Brochure: non-SI units accepted for use with the SI (minute, hour, day)

As of: 5 October 2026 · Editorial policy