32 free tools · no accounts · nothing uploaded

Time math,
without the math.

Calculators for everything measured in hours, minutes, and seconds — shifts and timesheets, business days and deadlines, timecode and cron, sleep and race pace. Each one runs instantly in your browser.

This page has been open for 00:00:00.0— every tool below answers in less.

Work & Payroll

Shift lengths, timesheets, overtime, and billable hours.

Shift Length CalculatorClock-in to clock-out, minus breaks.

Timesheet Decimal ConverterHours:minutes to payroll decimals, both ways.

Overtime CalculatorRegular, time-and-a-half, and double time split out.

Billable Hours CalculatorTime entries in, invoice total out.

Break Deduction CalculatorPaid span minus every break.

Weekly Shift TrackerA running total across the week's shifts.

Time and a Half CalculatorWhat 1.5× actually pays.

Dates & Projects

Business days, deadlines, countdowns, and calendar math.

Business Days CalculatorWorking days between two dates.

Sprint Deadline CalculatorWhen the sprint actually ends.

Age & Date Span CalculatorExact years, months, and days between dates.

Countdown to a DateA live timer to any moment.

Date Arithmetic CalculatorAdd or subtract days, weeks, months, years.

Workday & Holiday FilterN working days out, holidays excluded.

Week Number CalculatorISO week for any date.

Media & Video

Watch time, timecode, playlists, and playback speed.

Playback Speed CalculatorReal watch time at 1.25×, 1.5×, 2×.

SMPTE Timecode CalculatorAdd and subtract timecode at any frame rate.

Playlist Duration CalculatorPaste track times, get the total.

Audiobook Commute PlannerHow many commutes to finish the book.

Frames ↔ Timecode ConverterFrame counts to timestamps and back.

Podcast Time-Saved CalculatorWhat your listening speed earns you back.

Developer & Systems

Milliseconds, ISO 8601, epochs, and cron schedules.

Duration → Milliseconds Parser“1h 30m” to ms, seconds, and minutes.

ISO 8601 Duration ConverterPT1H30M, decoded and generated.

Unix Epoch Interval CalculatorThe exact span between two timestamps.

Time Expression CalculatorAdd and subtract durations like a calculator.

Cron Expression BuilderPoint, click, get the crontab line.

Military Time Converter0800 to 8:00 AM, both directions.

Everyday & Fitness

Sleep, running pace, time zones, and life milestones.

Sleep Cycle CalculatorWake times that respect your 90-minute cycles.

Running Pace CalculatorPace, time, or distance — solve for any.

Time Zone Meeting PlannerOne meeting, every city's clock.

Bond Duration CalculatorMacaulay and modified duration, priced.

Average Time CalculatorThe mean of a list of durations.

Billion-Second BirthdayThe day you turn 1,000,000,000 seconds old.

Built for the browser, and it stays there.

Every calculation on duration.tools happens on your device. No sign-up, no cookies beyond the essentials, no timesheet or birthday ever leaves the page. Open a tool, get the number, get on with your day.