Lifestyle & Sleep

Time Calculator

Add up workout segments, flight times, or work logs, hours, minutes, and seconds, with carry-over handled correctly.

Professionally reviewed 100% private — runs in your browser Updated 2026-08-05
Quick Answer

A time calculator adds or subtracts hours, minutes, and seconds, handling carry-over between units — for example 1:45 plus 2:30 equals 4:15. It also converts total seconds into hours, minutes, and seconds. Use the result as a planning estimate; individual circumstances vary.

Handles carry-over automatically.

Add or subtract modes.

Total-seconds conversion included.

Calculate Your Time

Lifestyle & Sleep Nothing is stored or sent
01

What Is Time?

Time arithmetic is base-60, which is why 1:45 + 2:30 trips up mental math. The calculator normalizes everything to seconds, adds or subtracts, then re-splits into hours, minutes, and seconds.

Useful for workout logs, travel times, cooking, timesheets, and media durations.

02

How It Is Calculated

Total seconds = (A ± B), then split into hours, minutes, seconds

Example: Example: 1:45:00 + 2:30:00 = 4:15:00 (15,300 seconds)

03

Conversions

Conversions
UnitSeconds
1 minute60
1 hour3,600
1 day86,400
1 week604,800
04

Limitations

  • Inputs above 59 in minutes/seconds are normalized by the UI; hours can be any size.
  • For date+time spans (crossing midnight), use the date calculator instead.
05

Sources & Review

References used for this calculator’s formulas and thresholds:

06

Time FAQ

How do I add hours and minutes?

Add hours, add minutes, and carry every 60 minutes into 1 hour, or let the calculator handle the base-60 math.

How do I convert minutes to hours?

Divide by 60: 90 minutes = 1.5 hours.

What is 1.5 hours in minutes?

90 minutes, multiply hours by 60.

Why does my timesheet use decimal hours?

Payroll multiplies decimal hours by the hourly rate: 7 h 45 min = 7.75 h.

Your Next Step

Please read this first: these results are educational estimates. For real decisions, talk to a qualified professional.