Time Calculator

About the Time Calculator

Adds or subtracts two durations expressed in hours, minutes and seconds, normalizing the result.

How to use

Enter both durations and choose add or subtract, then click Calculate.

Worked example

2h 45m + 1h 30m = 4h 15m.

How to use this calculator

1. Enter the starting time or amount.
2. Choose whether you want to add or subtract time.
3. Type in the hours, minutes, and seconds.
4. Click calculate to see the result and the step-by-step breakdown.

The formula explained

• \(\text{start time}\) = the original time value you begin with
• \(\text{duration}\) = the amount of hours, minutes, and seconds you add or subtract
• \(\text{final time}\) = the result after the time change

Step by step method

1. Begin with a starting time or time duration in the calculator.
2. Add or subtract each part of the time, keeping track of hours, minutes, and seconds.
3. Let the tool convert any overflow, such as 60 minutes into 1 hour, or any borrow needed for subtraction.
4. Read the instant result and review the worked steps if you want to check the logic.

Worked example

Suppose you start with 2 hours, 35 minutes, and 20 seconds and want to add 1 hour, 50 minutes, and 50 seconds.

1. Add the seconds first: \(20 + 50 = 70\) seconds, which becomes 1 minute and 10 seconds.
2. Add the minutes next: \(35 + 50 + 1 = 86\) minutes, which becomes 1 hour and 26 minutes.
3. Add the hours: \(2 + 1 + 1 = 4\) hours.
4. The result is 4 hours, 26 minutes, and 10 seconds.

Tips and common mistakes

• Check whether you are adding or subtracting before you enter the values.
• Remember that 60 seconds make 1 minute and 60 minutes make 1 hour.
• When subtracting, make sure borrowing is handled correctly across seconds and minutes.
• Use the worked example if you want to see how the calculator carries or borrows time.

Frequently asked questions