Time Tracking Calculator

You worked 6 hours 47 minutes on Tuesday and your invoicing software wants decimal hours. That's 6.78. The conversion is mechanical (minutes/60), but doing it for 14 entries by hand turns into the kind of small task that eats half an hour you could have billed.

Drop in your start time, end time, and any breaks. Get back the duration in both formats — hours-and-minutes for human reading, decimal hours for invoicing — plus the total pay if you put in an hourly rate.

Multiple entries can be added to a list and totaled, so a whole week's tracked time goes through in one pass instead of one row at a time.

The conversion between hours-and-minutes and decimal hours is mechanical: minutes / 60 = the decimal portion. So 30 minutes is 0.5 hours, 15 minutes is 0.25 hours, 45 minutes is 0.75 hours. Less round numbers: 47 minutes is 47/60 ≈ 0.7833 hours. Most invoicing systems standardize on decimal because addition and multiplication are simpler — 1.5 + 2.25 + 0.75 = 4.5 is faster than 1:30 + 2:15 + 0:45 = 4:30 across hour boundaries. For payroll calculations involving rate × time, decimal is mandatory.

A worked example for a billable day: you start at 9:14 AM, take a 47-minute lunch break, end at 5:23 PM. Total elapsed: 8 hours 9 minutes; minus break: 7 hours 22 minutes; in decimal: 7.367 hours. At a $125/hour rate, that's $920.83 billable for the day. If you'd rounded to the nearest 15 minutes (7.25 hours, $906.25), you'd be undercharging by $14.58 — small per day, $3,800 across a 250-day year. The choice of rounding convention is a real money decision, especially at higher rates.

The calculator handles the awkward cases: shifts that cross midnight (10:30 PM to 6:15 AM correctly returns 7 hours 45 minutes, not negative time), multiple breaks (just enter each separately), and unusual rate structures (overtime hourly rate after 40 hours per week, weekend differential). For consultancy work where each entry needs a project code, paste a list of entries and total per project — useful for monthly invoicing where you've worked across 5–10 clients.

Where it can mislead: the calculator doesn't know when you're 'on the clock' versus actually working. A 9-hour day with 4 hours of meetings, 2 hours of email, and 3 hours of focused work is 9 hours of paid time but maybe 3 hours of high-impact output. For salaried roles, the calculator-time isn't the productivity number; for hourly billable work, it is — your client paid for your attention, not your peak hours. This isn't a calculator problem; it's a self-management observation that the time you can charge for and the time that produced something you're proud of are not always the same.