FREE BUSINESS & PRODUCTIVITY TOOL

Time Calculator

Add or subtract hours and minutes, or find the time between two clock times. Instant answers, no signup and no tracking required.

✓ Free✓ Mobile friendly✓ Results stay on this device

First duration

HoursMinutes

Second duration

HoursMinutes

Minutes above 59 are carried into hours automatically, so 90 minutes counts as 1 hour 30 minutes. Results can exceed 24 hours.

Total duration2 hr 15 min135 total minutes · 2.25 decimal hours

How this tool works

Each duration is converted to minutes, added or subtracted, then turned back into hours and minutes. Minutes above 59 carry into hours, so entering 1 hour 90 minutes gives the same answer as 2 hours 30 minutes. The “Between times” option compares 24-hour clock values and can include a midnight crossing.

Useful for

Client work and billable hours
Shift and delivery planning
Study and event durations
Checking elapsed time across midnight

Examples you can check

Adding durations: 1 hour 30 minutes plus 45 minutes equals 2 hours 15 minutes. Enter the first duration as 1 hour and 30 minutes and the second as 0 hours and 45 minutes, then select Add time. This works for project tasks, estimated delivery windows and study sessions.

Subtracting durations: Start with a 4-hour budget and subtract 1 hour 50 minutes already used. The remaining duration is 2 hours 10 minutes. Negative results are displayed when the second duration exceeds the first, rather than silently changing the answer to zero.

Between two clock times: A shift starting at 9:00 AM and ending at 5:30 PM lasts 8 hours 30 minutes before breaks. For an overnight shift from 10:00 PM to 6:00 AM, enable the next-day option to receive 8 hours. Disable it when you deliberately want to see a negative same-day difference.

Frequently asked questions

Can a result exceed 24 hours? Yes. Adding or subtracting durations does not wrap at midnight, so the result can be longer than a day. The clock-time comparison uses one 24-hour day and an optional next-day crossing.

What is the difference between decimal hours and hours/minutes? Two hours 30 minutes is 2.50 decimal hours, not 2.30. Decimal hours are helpful for estimating tasks, but always follow your actual invoicing rules and rounding policy.

Is this suitable for payroll? It provides arithmetic, not employment-law or payroll calculations. It does not subtract unpaid breaks automatically, recognise public holidays, handle daylight-saving shifts or compute overtime premiums. Check local rules and documented work records before paying staff.

Is my data uploaded? The time fields and calculations run in this page's browser interface; this calculator does not send your entered durations to a time-tracking server. Avoid entering confidential business information into unrelated forms or shared devices.

This calculator uses local arithmetic only. It does not change for time zones or daylight-saving transitions.

Related free calculators

Estimating how many billable hours a process uses? Compare your assumptions with the AI Automation Savings Calculator, which includes setup and monthly running costs. Wondering what slow replies to new leads cost? The Cost of Lost Leads Calculator turns your first response time into an estimated customer and revenue gap. Planning a client website instead? The Small Business Website Cost Calculator estimates development scope separately from recurring expenses.

These tools answer different questions. Time arithmetic does not calculate payroll or automation returns on its own; use your actual business data and verify each estimate.