Strikeout-to-Walk Ratio Calculator
Calculate K/BB — strikeouts divided by walks — the classic measure of a pitcher's command.
Informational only — not a substitute for official league statistics or professional judgment.
How it's calculated
Assumptions
- Counts walks only (including intentional walks); hit-by-pitches are excluded per the official definition.
- Undefined when walks are zero — the calculator flags this rather than showing a number.
Source: MLB Glossary — Strikeout-to-Walk Ratio (K/BB)
Last reviewed: July 2026
Frequently asked questions
What's considered a good K/BB ratio?
In recent MLB seasons league average has sat around 2.5–2.8 strikeouts per walk. A K/BB above 3.0 reflects strong command, above 4.0 is excellent, and the very best control pitchers in a season can run ratios of 5.0 or higher.
What happens if a pitcher has zero walks?
K/BB is mathematically undefined with zero walks — you can't divide by zero. Stat sites typically display it as a dash or infinity until the pitcher issues a walk, which is one reason analysts often prefer K-BB% for small samples.
How is K/BB different from K-BB%?
K/BB divides total strikeouts by total walks, while K-BB% subtracts walk percentage from strikeout percentage (both measured per batter faced). K-BB% is better behaved in small samples and weighs strikeouts and walks more evenly, so modern analysts tend to prefer it.
Does K/BB account for innings pitched?
No — it's a pure ratio of two counting stats, so a reliever with 30 strikeouts and 10 walks scores the same 3.00 as a starter with 210 strikeouts and 70 walks. Use K/9 and BB/9 when you want rates scaled to innings.
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