Work Time Calculator: Add Up Your Hours and Breaks Fast

A work time calculator adds up hours and minutes across days or projects, converts between time units, and finds the duration between two times. Enter your time entries above — this free tool totals them, converts to decimal hours for invoicing, and even estimates earnings at your hourly rate.

Work time calculator adding hours and converting time units for freelancers

How Do You Use the Work Time Calculator?

Add time entries — hours and minutes per day, per project, or per task. As many rows as you need.
Or find a duration — enter a start and end time to get the time between them.
Convert units — switch between hours:minutes, decimal hours, and total minutes with one click.
Enter your hourly rate (optional) to turn total time into estimated earnings.

Tip: Freelancers — total your week in decimal hours (e.g., 21.58) and multiply by your rate. That’s your invoice number, no spreadsheet needed.

How Is Work Time Calculated?

Adding time: Add hours and minutes separately, then carry over every 60 minutes: 3h 45m + 5h 20m = 8h 65m = 9h 05m

Duration between two times: End − Start = Duration. If the end time is earlier (overnight), add 24 hours first: 2:00 PM → 10:00 PM = 8 hours; 10:00 PM → 6:00 AM = 8 hours

Unit conversions: Minutes → decimal hours: minutes ÷ 60 (90 min = 1.5h). hh:mm → decimal: hours + (minutes ÷ 60) (7:30 = 7.5). Decimal → hh:mm: 0.5h × 60 = 30 min (7.5 = 7:30).

Earnings estimate: Total decimal hours × hourly rate = estimated pay

Worked Example: Priya’s Freelance Week

Meet Priya. She’s a freelance designer in Chicago billing at $75/hour. Her project hours this week:

Day	Hours
Monday	3h 45m
Tuesday	5h 20m
Wednesday	2h 15m
Thursday	6h 05m
Friday	4h 10m

Step 1 — Add hours: 3 + 5 + 2 + 6 + 4 = 20 hours

Step 2 — Add minutes: 45 + 20 + 15 + 5 + 10 = 95 minutes = 1h 35m

Step 3 — Total: 20h + 1h 35m = 21h 35m

Step 4 — Decimal: 21 + (35 ÷ 60) = 21.58 hours

Step 5 — Invoice: 21.58 × $75 = $1,618.75 → $1,619

One page, five steps, invoice-ready number.

Work Time Calculator vs. Time Clock Calculator

Feature	Work Time Calculator	Time Clock Calculator
What it does	Adds durations, converts units, finds time between times	Weekly timesheet from clock-in/out
Breaks	Not tracked	Unpaid breaks subtracted
Overtime	No	Yes, FLSA 40h rule
Best for	Freelancers, invoicing, general time math	Employees, payroll timesheets

Need a weekly timesheet with overtime? Use our time clock calculator.

Frequently Asked Questions

A time clock calculator is built for weekly timesheets — clock-in/out per day, breaks, overtime. A work time calculator is broader: adding up arbitrary time durations, converting units, and finding time between any two points.

Add hours and minutes separately, then convert every 60 minutes into an hour: 3h 45m + 5h 20m = 8h 65m → carry 60 → 9h 05m. The calculator above does the carrying automatically.

Divide the minutes by 60 and add: 30 ÷ 60 = 0.5, so 7:30 = 7.5 hours. Payroll and invoicing almost always want decimals.

Log start/end times daily (don’t reconstruct Friday from memory), total them weekly in decimal hours, and multiply by your rate. Most freelancers round to the nearest 15 minutes per entry — just say so in your contract.

It handles time-of-day durations including overnight spans. For multi-day project totals, add each day’s hours as separate entries.

Yes — everything runs in your browser. Your hours and rates never leave your device.

Related Calculators

Time Clock Calculator — weekly timesheets with breaks and overtime

Salary to Hourly Calculator — know your effective hourly rate

Paycheck Calculator — see take-home pay after taxes

This calculator is for educational and planning purposes only — not payroll, tax, or legal advice. Overtime and break rules vary by state and employer.

Sources

U.S. Department of Labor — Overtime Pay
U.S. Department of Labor — Hours Worked Under the FLSA