A time calculator performs arithmetic on time values — adding, subtracting, and finding differences between durations or clock times. Unlike regular arithmetic, time uses base-60 for minutes and seconds. Our calculator handles the conversions automatically, showing results in HH:MM:SS format, total minutes, and decimal hours.
Time Calculator
Our Time Calculator handles all common time math operations in one place. Use Add/Subtract mode to combine or remove time durations — perfect for calculating total work time, adding up meeting durations, or planning schedules. Use Time Difference mode to find exactly how many hours, minutes, and seconds are between two clock times — great for tracking work shifts, measuring elapsed time, or planning travel. All results are shown in HH:MM:SS, total minutes, and decimal hours simultaneously.
star
4.9
calendar_today
Updated: April 2026
auto_awesome
AI Insights
AI
New
timer Time Range
Quick Examples
add_circle Time Values
Format: HH:MM or HH:MM:SS (e.g. 1:30, 2:45:30)
calculate Result
auto_awesome AI Analysis
Powered by ClaudeEnter your values and calculate to receive AI-powered insights about your results.
schedule Time Conversions
Decimal Hours
hours = minutes ÷ 60
To Hours:Mins
1.5h = 1h 30m
Total Seconds
H×3600 + M×60 + S
AM/PM → 24h
PM (not 12): +12h
Midnight Cross
End < Start → +24h
payments Common Decimal Hours
15 min
= 0.25 h
30 min
= 0.5 h
45 min
= 0.75 h
1h 20m
= 1.333 h
7h 30m
= 7.5 h
8h 45m
= 8.75 h
lightbulb Quick Tips
- •Enter 9:00 AM or 09:00 — both work
- •Add break minutes for net payroll hours
- •Overnight: 10 PM to 6 AM = 8 hours
- •Decimal × hourly rate = pay amount
- •Add mode: total up multiple work blocks
How to Use This Calculator
1
Choose Mode
Select Add Times to combine durations, Subtract to remove time, or Time Difference to find the gap between a start and end time.
2
Enter Times
Type times in HH:MM or HH:MM:SS format. For Time Difference mode, enter start and end times with optional AM/PM.
3
Add Break (Optional)
In Time Difference mode, enter break duration in minutes to calculate net work time automatically.
4
Read Results
See the result in HH:MM:SS, total minutes, decimal hours, and a breakdown of hours and minutes separately.
The Formula
Time arithmetic works in base-60: 60 seconds = 1 minute, 60 minutes = 1 hour. To add durations, convert everything to seconds, sum, then convert back. For time difference, subtract start from end (handling midnight crossover). Decimal hours = total_minutes / 60.
Difference = End Time − Start Time | Sum = T₁ + T₂ + ... + Tₙ
lightbulb Variables Explained
- HH:MM:SS Hours : Minutes : Seconds format
- Decimal hours Total hours expressed as a decimal (e.g., 1.5 = 1h 30m)
- Total minutes Duration expressed as total minutes
- AM/PM 12-hour clock format — AM = morning (midnight to noon), PM = afternoon (noon to midnight)
tips_and_updates Pro Tips
1
Use HH:MM:SS format for precise time entry, or just HH:MM if seconds aren't needed
2
Decimal hours are useful for payroll: 8.5 hours = 8 hours 30 minutes
3
When calculating overnight shifts (e.g., 10 PM to 6 AM), the calculator handles midnight crossover automatically
4
Add multiple time blocks by summing them: meeting 1 (45 min) + meeting 2 (1:15) + prep (30 min) = 2:30 total
5
Total minutes ÷ 60 = decimal hours. Example: 90 minutes ÷ 60 = 1.5 hours
6
For payroll with breaks, use Time Difference mode and enter break minutes to get net work time
Time calculators are used for payroll and work hours tracking, scheduling and planning meetings, tracking project time, calculating shift durations, billing by time (legal, consulting), fitness and workout timing, travel duration planning, and academic exam timing.
Frequently Asked Questions
Related Tools
View all Math View all arrow_forward
sell
Tags
verified
Data sourced from trusted institutions
All formulas verified against official standards.