Code Review Time Calculator
Review hours from lines changed.
Enter your values
Enter the lines changed you are working with.
Enter the review rate in lines/hour.
Enter the reviewers you are working with.
Enter the defects per kloc you are working with.
Results update instantly as you type — no submit needed. Your values are remembered on this device, and the shareable link reopens the calculator with exactly these numbers.
- Review hours per reviewer
- 2.83
- Total team hours
- 5.67
- Expected defects
- 10.2
- PR size verdict
- Too large — split it
Quick answer
Effective code review runs at 200–400 lines per hour; faster reviews miss defects.
Hours = lines ÷ review rate
At a glance
| What it does | Review hours from lines changed. |
|---|---|
| Category | Technology |
| Inputs needed | Lines changed, Review rate, Reviewers, Defects per KLOC |
| Main output | Review hours per reviewer |
| Formula | Hours = lines ÷ review rate |
| Cost | Free — no sign-up, no download |
How to use the Code Review Time Calculator
- 1Enter lines changed in the pull request.
- 2Set your team's review rate.
- 3Enter how many reviewers are assigned.
Inputs explained
- Lines changed
- Enter the lines changed you are working with.
- Review rate(lines/hour)
- Enter the review rate in lines/hour.
- Reviewers
- Enter the reviewers you are working with.
- Defects per KLOC
- Enter the defects per kloc you are working with.
Worked example
Using the values the calculator loads with:
Inputs
- Lines changed850
- Review rate300 lines/hour
- Reviewers2
- Defects per KLOC12
Results
- Review hours per reviewer2.83
- Total team hours5.67
- Expected defects10.2
- PR size verdictToo large — split it
Frequently asked questions
What PR size is ideal?
Under 400 lines — defect detection collapses beyond that.
Do two reviewers double detection?
No, the second reviewer adds far less than the first.
What do I need to enter into the Code Review Time Calculator?
Just 4 values: lines changed, review rate, reviewers, defects per kloc. Every field starts with a realistic example, so you can change one number at a time and watch the result update instantly.
How does the Code Review Time Calculator work out the answer?
Effective code review runs at 200–400 lines per hour; faster reviews miss defects. It applies the formula Hours = lines ÷ review rate and shows the working so you can check each step by hand.
Is the Code Review Time Calculator free, and do I need an account?
It is completely free with no sign-up, no download and no usage limit. Everything is calculated in your browser, so the numbers you type never leave your device.
Results are estimates for general information. For medical, legal, structural or financial decisions, confirm with a qualified professional.