Baseball ERA and WHIP Calculator
Earned run average, WHIP, strikeouts and walks per nine innings and strikeout-to-walk ratio from a pitcher's line.
Results
What this tool does
The classic trap with pitching stats is the innings column: 6.2 innings does not mean 6.2 but six innings and two outs, 6⅔. That is why the outs go in their own field here, and why calculating ERA from the box-score figure as a decimal gives the wrong answer. ERA scales earned runs to a full nine-inning game; unearned runs, those that scored because of an error, are left out. WHIP is simpler and does not depend on the official scorer's judgement about errors, and recently a league-average starter sits around a 4.00 ERA and a 1.30 WHIP, while under 1.00 WHIP is elite.
Formula
ERA = 9 × ER ÷ IP · WHIP = (BB + H) ÷ IP · K/9 = 9 × SO ÷ IP
Variables
| Symbol | Meaning | Unit |
|---|---|---|
ip | Innings pitched, whole innings | — |
ou | Plus outs (the .1 or .2) | — |
er | Earned runs (ER) | — |
h | Hits allowed (H) | — |
bb | Walks allowed (BB) | — |
so | Strikeouts (SO) | — |
ER | Earned run average (ERA) | — |
WH | WHIP (walks and hits per inning) | — |
K9 | Strikeouts per 9 innings | — |
B9 | Walks per 9 innings | — |
KB | Strikeout-to-walk ratio | — |
IP | Innings as a true decimal | — |
Worked example
- Innings pitched, whole innings180
- Plus outs (the .1 or .2)0
- Earned runs (ER)60
- Hits allowed (H)160
- Walks allowed (BB)50
- Strikeouts (SO)190
- Earned run average (ERA)3.00
- WHIP (walks and hits per inning)1.167
- Strikeouts per 9 innings9.50
- Walks per 9 innings2.50
- Strikeout-to-walk ratio3.80
- Innings as a true decimal180.000
Limitations
- The calculation runs at full precision and only the display is rounded. If you copy an intermediate value and retype it, small differences can appear.