TCalc: Time & Hours Calculator

TCalc is a time calculator and time converter that actually understands time. Add and subtract hours and minutes, multiply durations, get the difference between clock times, add working days to a date, and do frame-accurate SMPTE timecode math — all in one calculator.

Type it like you say it:
• 7h 45m × 5 = 38h 45m
• 17:30 − 9:00 − 45m = 7h 45m
• NOW + 3d 4h = your deadline, done
• 01:00:00:00 + 00:00:10:12 (24 fps) = 01:00:10:12

WHO IT'S FOR
• Freelancers & HR — add up timesheets, decimal hours and work hours in seconds
• Video editors — SMPTE timecode calculator with 24/25/30/60 fps support
• Developers — Unix epoch, ISO 8601 and duration conversions
• Pilots — Zulu (UTC) time, fuel reserves and decimal logbook hours
• Truckers & nurses — duty time, drive limits and shift math
• Everyone — how long until my flight? What time is 6h 30m from now?

TIME CONVERTER — TIMES & DATES
• Live converter widgets: the current time in 24h, 12h, military, Zulu (UTC), ISO and Unix at once — on your home screen or in the app
• Unix timestamp → date & time, and back (1736861234 → Jan 14, 2026)
• Decimal hours for payroll & invoicing (7h 30m → 7.5h)
• Military ↔ standard time (17:30 ↔ 5:30 PM)
• Durations to minutes, seconds, days or frames at any fps
• Date & time to ISO 8601, Zulu (UTC) or your local format

FEATURES
• Natural input: mix durations (2h 30m), clock times (17:30) and dates
• 8 profession keypads: Everyday, Film, Military, Aviation, Developers, HR, Accounting and Logistics
• Time & date difference calculator with DST-aware option
• Duration formats: compact, hours, minutes, seconds, days or timecode
• One-tap converters: decimal hours, military time, Unix timestamp, timecode
• Custom calculator keys — save your own shortcuts like Work Day or Sprint
• Home-screen widgets: live multi-format clock and a one-tap quick calculator
• Calculation history with free cloud sync when you sign in
• Works offline — the calculator runs entirely on your device
• Dark, native Material design built for one-hand use

FAIR PRICING
The calculator is free — every unit, every format, no account needed. Pro unlocks all profession keypads and unlimited custom buttons for a single one-time purchase. No subscription, no recurring charges, and everything you buy keeps working offline.

Also available in any browser at tcalc.it — one account, same calculator everywhere.

Time math is everywhere: timesheets, overtime, edit timelines, flight plans, cooking, workouts. Stop converting minutes in your head — type it like you say it and let TCalc do the rest.