Time Calculator
Add or subtract durations in hours, minutes and seconds.
Last updated: January 2025 · Built for the 2024–25 financial year
Inputs
Time 1
Time 2
Results
Result
4h 15m 0s
Total minutes
4h 15m
Decimal hours
4.250
Results are estimates only. For financial advice, consult a licensed adviser.
Overview
Add, subtract & convert time intervals
Time arithmetic frequently mixes units — hours, minutes, seconds — and bases (60 not 100). 1.75 hours is 1 hour 45 minutes, not 1 hour 75 minutes. Decimal time is what payroll and project tools use.
Useful for shift maths, project tracking, video editing, race timing and converting between time-zone offsets.
Formula
Conversions
decimal hrs = hrs + min/60 + sec/3600 sum = align all to seconds, sum, convert back
Pro tips
- •Use 24-hour notation to avoid AM/PM bugs.
- •Time-zone calculations: convert to UTC first, then to target zone.
- •DST switches twice a year — check before scheduling.