What WHIP measures
WHIP stands for Walks plus Hits per Inning Pitched. It is one of the most widely used rate statistics for evaluating a pitcher because it answers a simple question: how many baserunners does this pitcher allow, on average, in each inning? A pitcher who keeps runners off base gives up fewer scoring chances, so a lower WHIP is always better. Unlike ERA, WHIP is not affected by the fielding, sequencing, or luck that determines whether those baserunners eventually score — it isolates a pitcher's ability to prevent walks and hits in the first place.
The WHIP formula
The calculation is a straightforward rate:
WHIP = (Walks + Hits) ÷ Innings Pitched
Add a pitcher's total bases on balls (BB) to the total hits allowed (H), then divide by innings pitched (IP). For example, a pitcher with 45 walks and 150 hits over 180 innings has (45 + 150) / 180 = 195 / 180 = 1.083. Only walks and hits count as baserunners for WHIP. Batters who reach on a hit-by-pitch, an error, a dropped third strike, or a fielder's choice are deliberately excluded, which is why WHIP is not a complete count of every runner a pitcher put on base.
Handling fractional innings
Baseball records innings pitched in thirds, because each out retires one-third of an inning. In a box score, "6.1 IP" means six and one-third innings and "6.2 IP" means six and two-thirds innings — the decimal is a count of outs, not a true tenth. Before dividing, convert those figures: 6.1 IP becomes 6.333 and 6.2 IP becomes 6.667. Entering "6.1" literally would slightly understate the innings and inflate the WHIP. This calculator divides by whatever decimal you enter, so convert thirds to true decimals (add 0.333 or 0.667) for an exact result.
What counts as a good WHIP
WHIP benchmarks shift with the run-scoring environment, but modern Major League reference points are stable enough to judge a season:
- Under 1.00 — Elite. A sub-1.00 WHIP means fewer than one baserunner per inning and is rare over a full season; it typically leads the league.
- 1.00 to 1.10 — Excellent. The range of Cy Young contenders and front-line aces.
- 1.10 to 1.25 — Above average. Solid, reliable starters live here.
- Around 1.30 — League average for a starting pitcher in a typical MLB season.
- 1.40 to 1.50 — Below average. The pitcher is allowing a lot of traffic on the bases.
- Above 1.50 — Poor, and usually unsustainable for a rotation spot.
For historical context, Pedro Martinez set the single-season record with a 0.7373 WHIP in 2000, and career leaders such as Addie Joss and Ed Walsh sit near 1.00 across thousands of innings.
WHIP versus ERA
ERA (earned run average) measures the runs a pitcher gives up per nine innings; WHIP measures the baserunners allowed per inning. The two usually move together, but not always. A pitcher can post a high WHIP yet a low ERA by stranding runners and inducing double plays — an outcome that often regresses over time. Because WHIP strips out the noise of when and whether runners score, many analysts treat it as a better indicator of the underlying skill a pitcher will carry into future outings. The two stats are strongest read side by side.