Code Review Coverage Calculator

Quantify review coverage and consistency. Compare line and PR reach. Spot thin-review risk fast. Make reviews predictable across every delivery cycle.

Calculator

Enter your repository metrics for a sprint, week, or release window.

Sum of added + modified lines.
Lines touched in reviewed diffs.
All PRs merged in the window.
PRs with required reviewers completed.
Issues caught before merge.
Total reviewer time for the window.
Total engineering hours (excluding review).
Higher favors reviewing more changed code.
Higher favors ensuring all PRs are reviewed.
Reset
Tip: Use the same time window every run for reliable trend tracking.

Formula used

Line Coverage (%)

line_coverage = (reviewed_lines / total_lines) × 100


PR Coverage (%)

pr_coverage = (reviewed_prs / total_prs) × 100

Weighted score (%)

score = (line_cov×w_line + pr_cov×w_pr) / (w_line + w_pr)


Effort + penalty

effort = (review_hours / dev_hours) × 100

penalty = max(0, (10 − effort)/10 × 15)

adjusted = clamp(score − penalty, 0, 100)

Defects per KLOC reviewed

defects_per_kloc = defects_found / (reviewed_lines / 1000)

This is a signal, not a target. Very low values can mean shallow reviews.

How to use this calculator

  1. Pick a consistent window: weekly, sprint, or release.
  2. Collect totals: changed lines, PR count, and review completion.
  3. Add reviewer time and development time from your tracking.
  4. Adjust weights to match your policy and risk tolerance.
  5. Run the calculator and compare scores across windows.
  6. Export CSV for trend charts and audit trails.

Example data table

These rows show typical sprint metrics and results.

Window Changed LOC Reviewed LOC Total PRs Reviewed PRs Defects Review hrs Dev hrs Adj. score Rating
Sprint 121800160022211418.512083.9%Good
Sprint 132400170026231114.013566.8%Fair
Sprint 14150014801919917.011094.1%Excellent

Your recent history (saved runs)

Date Line cov PR cov Effort Defects/KLOC Adj. score Rating
No saved runs yet. Enable “Save this run to history”.

FAQs

1) What is code review coverage?

It estimates how much work was checked by reviewers. This calculator reports coverage by changed lines and by pull requests.

2) Why track both line coverage and PR coverage?

Line coverage captures depth across changed code. PR coverage captures process compliance, ensuring every change gets reviewed.

3) What does “review effort” mean here?

Review effort is review hours as a percentage of development hours. Very low effort can make high coverage look better than it is.

4) Does a higher defects-per-KLOC value mean worse code?

Not always. A moderate value can mean reviewers are catching real issues. Extremely low values may indicate reviews are superficial.

5) How should we choose weights?

If you fear unreviewed PRs, increase PR weight. If large diffs slip through, increase line weight. Keep weights stable for trend tracking.

6) Can this replace automated tests or static analysis?

No. Reviews are complementary. Use this score alongside test coverage, CI quality gates, and production incident metrics.

7) What score should we aim for?

Many teams target 75–90% adjusted score, depending on risk. The best target is one that predicts fewer escapes and stable delivery.

Related Calculators

Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.