Time Calculator
Calculate time differences, add or subtract time, or convert between hours, minutes and seconds — instantly, for free.
What Is a Time Calculator?
A time calculator helps you calculate time differences, add or subtract time, and convert between hours, minutes, and seconds. It removes the manual math of carrying over 60-minute and 60-second boundaries, which is where most people make mistakes doing this by hand. It's commonly used for payroll, scheduling, cooking, travel planning, and tracking work hours.
How to Use This Time Calculator
- Choose a calculation type: Time Difference, Add/Subtract Time, or Convert Time.
- Enter the time values in hours, minutes and seconds using 24-hour format.
- Click "Calculate" to see your result, broken down into hours, minutes, seconds, and totals.
Worked Examples
Time Difference
Start: 9:30 AM End: 5:45 PM
Result: 8 hours, 15 minutes elapsed
Add Time
Base: 9:30 AM Add: 2 hours, 15 minutes
Result: 11:45 AM
Convert Time
Time: 1 hour, 30 minutes
Result: 90 minutes / 5,400 seconds
Common Use Cases
Work Hours Tracking
Calculate total hours worked including breaks, and figure out overtime pay.
Project Deadlines
Add turnaround time to a start time to find an accurate deadline.
Cooking & Baking
Stack multiple prep and cook times to plan when a dish will be ready.
Travel & Flight Layovers
Work out layover duration or total travel time across a multi-leg trip.
Frequently Asked Questions
What is the difference between time difference and add/subtract?
Time difference calculates the gap between two clock times. Add/subtract adds or removes a duration from a single base time.
How do I convert time to minutes?
Multiply hours by 60, add the minutes, then add seconds divided by 60.
Can I calculate negative time?
Yes — subtracting a larger time from a smaller one returns a negative result.
Does this handle times past midnight?
Enter times in 24-hour format and the calculator returns the correct elapsed duration across midnight.
Is this calculator free?
Yes, completely free with no sign-up, on both desktop and mobile.