Baseball has always been a sport driven by numbers, and baseball is a game of statistics that fans use to compare players across eras. For decades the go-to number for judging a pitcher was earned run average (ERA). More recently, a second statistic has become just as common on broadcasts and box scores: WHIP, short for walks plus hits per inning pitched. This guide explains what WHIP is, how to calculate it, what counts as a good figure, and why it is often used alongside ERA rather than instead of it.
Key Points
- WHIP = walks plus hits per inning pitched — the number of baserunners a pitcher allows per inning.
- Formula: (Walks + Hits) ÷ Innings Pitched, shown to three decimal places.
- Runs, hit-by-pitch, errors and fielder’s-choice runners are not included.
- Lower is better: under 1.00 is elite, around 1.30 is the modern MLB average.
- Best read alongside ERA, not instead of it.
Earned run average (ERA): the starting point
To understand why WHIP exists, it helps to start with the statistic it is usually compared against. ERA is the most widely quoted pitching number — it is typically the first figure shown when a new pitcher enters a game, and it is written as a decimal such as 3.45.
ERA measures the average number of earned runs a pitcher allows per nine innings. You calculate it by dividing the earned runs a pitcher has allowed by their innings pitched, then multiplying by nine. For a full breakdown, see our guide to what earned run average (ERA) means.
An earned run is a run the defence could not have prevented through clean play. If a batter reaches base by a hit, a walk, or a hit-by-pitch and later scores, that is an earned run charged to the pitcher. Runs that only score because of a fielding error or a passed ball are unearned and do not count toward ERA. As a rough guide, an ERA under 4.00 is considered good and truly elite starters sit under 3.00. The lowest career ERA of any live-ball-era pitcher (post-1920) with at least 1,000 innings belongs to Hall of Fame reliever Mariano Rivera, at 2.21.
The drawbacks of ERA
ERA is a reliable measure of how many runs a pitcher gives up, but it is not a perfect gauge of individual performance. Limiting runs is arguably the most important part of the pitcher’s job, yet ERA can hide how much traffic a pitcher allows on the bases.
A pitcher who constantly puts runners on base but repeatedly escapes trouble can post a low ERA thanks to good fortune, strong fielding, or well-timed strikeouts. ERA also depends partly on the defence behind the pitcher and on the official scorer’s decision about what counts as an error. Those factors sit outside the pitcher’s direct control, which is where WHIP comes in.
What WHIP actually measures
WHIP measures how many baserunners a pitcher allows for every inning they pitch. Unlike ERA, runs are not part of the calculation at all. Only three inputs matter: walks (bases on balls), hits, and total innings pitched.
Importantly, batters hit by a pitch are not counted in WHIP, and neither are runners who reach base on an error or a fielder’s choice. Only walks and hits go into the top of the equation. The formula is:
WHIP = (Walks + Hits) ÷ Innings Pitched
Here “Walks” (BB) means bases on balls, “Hits” (H) means hits allowed, and “Innings Pitched” (IP) is the number of innings the pitcher has thrown.
How to calculate WHIP: a worked example
Suppose a starter throws 200 innings in a season and allows 150 hits and 40 walks. Add the walks and hits together (40 + 150 = 190), then divide by innings pitched (190 ÷ 200). That gives a WHIP of 0.95.
WHIP is written to three decimal places. A WHIP of 1.000 means the pitcher allows exactly one baserunner (via walk or hit) per inning. The fewer walks and hits a pitcher gives up, the lower and better the number. Elite pitchers regularly finish a season near or below 1.00. Among starting pitchers in the live-ball era with at least 1,000 innings, Jacob deGrom holds the lowest career WHIP at roughly 0.99 — for reference, Mariano Rivera’s career WHIP as a reliever was 1.00.
What counts as a good WHIP?
Context matters, because scoring environments change over time, but the modern Major League Baseball average sits around 1.30. The table below shows how WHIP figures are generally interpreted for starting pitchers. These bands are guidelines, not official cut-offs.
WHIP Benchmarks
| WHIP range | General rating |
|---|---|
| Under 1.00 | Elite — dominant, Cy Young-calibre |
| 1.00 – 1.20 | Excellent — front-of-rotation ace |
| 1.20 – 1.30 | Good — solid, reliable starter |
| 1.30 – 1.40 | Average — around the league norm |
| 1.40 – 1.50 | Below average — too many baserunners |
| Over 1.50 | Poor — command or contact problems |
ERA and WHIP: better together
Neither statistic tells the whole story on its own. ERA answers a simple question — how many runs did the pitcher give up? — while WHIP answers a different one: how often did the pitcher let batters reach base in the first place? A pitcher with a low WHIP but a higher ERA may be unlucky with runners scoring, while a low ERA paired with a high WHIP can hint at fortunate escapes that may not last.
Used together, the two numbers give a fuller picture. The very best pitchers post a low mark in both. WHIP also pairs naturally with hitting-side metrics such as OPS for hitters, since both aim to capture value that older, simpler stats miss. If you are still learning the vocabulary, our baseball terms glossary is a useful companion.
Common misunderstandings about WHIP
- Lower is better. Unlike batting stats where higher is stronger, a smaller WHIP is the goal.
- It is not a rate per nine innings. WHIP is baserunners per single inning, so its scale is very different from ERA.
- It ignores hit-by-pitch. A pitcher who hits many batters can still post a tidy WHIP, so the number does not capture every baserunner.
- It does not weight the type of hit. A single and a home run count the same in WHIP, which is why it is best read alongside other statistics rather than alone.
Sources
Vanliga frågor (FAQ)
What does WHIP stand for in baseball?
WHIP stands for walks plus hits per inning pitched. It measures how many baserunners a pitcher allows, on average, for every inning they throw.
How do you calculate WHIP?
Add the pitcher’s walks and hits allowed, then divide by their innings pitched. For example, 40 walks plus 150 hits over 200 innings is (40 + 150) ÷ 200 = 0.95.
What is a good WHIP?
A WHIP under 1.00 is elite, roughly 1.00 to 1.20 is excellent, and around 1.30 is close to the modern MLB league average. Figures above about 1.40 are generally seen as below average for a starter.
Does WHIP include hit by pitch?
No. Only walks and hits are counted. Batters hit by a pitch, runners who reach on an error, and fielder’s-choice runners are all excluded from WHIP.
Is WHIP better than ERA?
Neither is strictly better. WHIP shows how often a pitcher lets batters reach base, while ERA shows how many runs they give up. Reading the two together gives the most complete view of a pitcher’s performance.
