What Does WHIP Mean in Baseball? Formula, Examples and Limits
What does WHIP mean in baseball? It is walks plus hits per inning pitched. Learn the formula, how partial innings work, and what the stat does not measure.
WHIP stands for walks and hits per inning pitched. To get it, you add up the walks and hits a pitcher has allowed and divide by the innings that pitcher has thrown. The result shows how many batters reached base on a hit or a walk per inning, and MLB’s glossary links a low WHIP with the league’s top pitchers.
The WHIP Formula
MLB’s glossary adds walks and hits together, then divides by innings pitched:
WHIP = (Walks + Hits) / Innings Pitched
The glossary lists WHIP among the stats used most often to judge pitchers. Its point is simple: it tracks how well a pitcher stops batters from getting on base, which the glossary names as one of a pitcher’s main goals.
What Counts as a Walk and a Hit
Both inputs are recorded by the official scorer under MLB’s Official Baseball Rules.
- Walk. The rulebook term is base on balls. A batter earns first base once four pitches have missed the strike zone. The rules also let the defensive manager tell the umpire the batter should go to first, and the scorer records that as an intentional base on balls. One detail: if the fourth ball hits the batter, the scorer records a hit batter, not a walk.
- Hit. The rulebook calls it a base hit, credited when a batter reaches base safely on a fair ball under the conditions set out in the scoring rules. Singles, doubles, triples and home runs all go into the same hit total that WHIP uses.
How Innings Pitched Work
MLB’s glossary explains that every out recorded while a pitcher is in the game is worth one third of an inning for that pitcher, because an inning holds three outs. The Official Baseball Rules define an inning as the part of a game in which the teams take turns on offense and defense, with three putouts for each team. A double play is worth two thirds. The pitcher has to be in the game when the out happens for the total to go up.
So a pitcher who gets two outs and then leaves has two thirds of an inning, not a full one. Before you divide, turn any partial inning into thirds. The rulebook takes the same approach for earned run average, telling scorers to divide by innings pitched “including fractions of an inning.”
Worked Examples
A Simple Case
A pitcher has given up 30 hits and 6 walks across 30 innings.
- Walks plus hits: 30 + 6 = 36.
- Divide by innings: 36 / 30 = 1.20.
That WHIP of 1.20 means 1.2 batters per inning, on average, reached by a hit or a walk.
A Case With Partial Innings
Another pitcher has given up 18 hits and 5 walks across 20 and two-thirds innings.
- Walks plus hits: 18 + 5 = 23.
- Write the innings as a decimal: 20 and two-thirds is about 20.667.
- Divide: 23 / 20.667 is about 1.11.
If the two thirds were dropped and you divided by 20, you would get 1.15, so the fraction changes the answer.
A Short Relief Outing
A reliever has allowed 4 hits and 3 walks in 5 and one-third innings.
- Walks plus hits: 4 + 3 = 7.
- Innings as a decimal: 5 and one-third is about 5.333.
- Divide: 7 / 5.333 is about 1.31.
What WHIP Leaves Out
The MLB glossary points out that WHIP ignores the way a batter got on base beyond walks and hits. Per the glossary, a batter hit by a pitch, a runner safe on an error, and a fielder’s-choice runner are all left out of the count.
Where WHIP Came From
MLB’s glossary traces the term to 1979. A writer credited with creating rotisserie-style fantasy baseball came up with it, and it started out under the name “innings pitched ratio” before becoming WHIP.
WHIP Next to ERA
WHIP and earned run average (ERA) are both pitching rate stats, but they count different things.
- WHIP counts baserunners from walks and hits, per inning.
- ERA counts earned runs. The rulebook formula multiplies earned runs by 9 and divides by innings pitched.
The rulebook’s own ERA example, 3 earned runs in 9 and one-third innings, comes out to 2.89. Both stats use innings pitched as the divisor, including partial innings, so the same care with thirds applies to each.
Frequently Asked Questions
Is a lower WHIP better?
Yes. MLB’s glossary ties the lowest WHIPs to the league’s best pitchers. A lower number means fewer batters reached on walks and hits each inning.
Do hit-by-pitches count in WHIP?
No. Per the MLB glossary, a batter hit by a pitch is not part of WHIP, and neither is a runner safe on an error or a runner who reaches on a fielder’s choice. Only walks and hits are added up.
How is WHIP different from ERA?
WHIP divides walks plus hits by innings pitched. ERA multiplies earned runs by 9 and divides by innings pitched. One measures baserunners, the other measures earned runs.
