OPS calculator
Type a hitter's counting stats and this OPS calculator works out on-base percentage, slugging percentage and OPS (on-base plus slugging) with the official formulas, to three decimals.
OPS calculator tool
How to use the OPS calculator
- Enter at-bats and total hits, then how many of those hits were doubles, triples and home runs.
- Enter walks (intentional walks included), hit by pitch and sacrifice flies. Leave a box empty if the number is zero.
- Read OPS at the top, with OBP, SLG, batting average and total bases underneath, and the exact divisions used.
The formulas
OBP = (H + BB + HBP) ÷ (AB + BB + HBP + SF)
TB = 1B + 2×2B + 3×3B + 4×HR · SLG = TB ÷ AB
OPS = OBP + SLG
On-base percentage is how often a batter reaches base by a hit, a walk or being hit by a pitch. Reaching on an error or a fielder's choice does not count as reaching base here. Slugging percentage is total bases per at-bat, so a home run is worth four times a single. OPS simply adds the two, which rewards getting on base and hitting for power in one number. It is crude (a point of OBP is worth more to a team than a point of SLG) but it is easy to work out and tracks run scoring well.
Worked example
The values already in the OPS calculator above: 520 AB, 150 H, 30 2B, 3 3B, 25 HR, 60 BB, 5 HBP and 5 SF.
- Singles = 150 − 30 − 3 − 25 = 92.
- Total bases = 92 + 2×30 + 3×3 + 4×25 = 92 + 60 + 9 + 100 = 261.
- OBP = (150 + 60 + 5) ÷ (520 + 60 + 5 + 5) = 215 ÷ 590 = 0.36441 → .364.
- SLG = 261 ÷ 520 = 0.50192 → .502.
- OPS = 0.36441 + 0.50192 = 0.86633 → .866.
The same hitter's batting average is 150 ÷ 520 = .288. The walks lift OBP 76 points above the average, and the 58 extra-base hits push slugging over .500.
Common mistakes
- Using plate appearances as at-bats. Slugging divides by at-bats only. If you enter plate appearances, every walk and sacrifice is treated as an out and SLG comes out too low.
- Counting home runs as singles too. Hits already include doubles, triples and home runs. Enter the total once in Hits and the extra-base hits in their own boxes.
- Leaving out hit by pitch. HBP is part of on-base percentage. A hitter who crowds the plate can gain 10 points of OBP or more from it over a season.
- Adding sacrifice bunts. They are not part of either formula, so there is no box for them.
What is a good OPS?
As a rough MLB guide only: around .700 to .750 is close to league average in recent seasons, .800 and up is very good, .900 and up is star level, and 1.000 or more over a full season is rare. Youth, college and softball numbers run on different scales, so compare players in the same league.
Tips
- Check the singles figure shown with the result. If it looks wrong, a double or home run was probably also counted in the wrong box.
- Want only the power part? The slugging percentage calculator also shows isolated power (ISO).
- For a quick hits-only number use the batting average calculator; for pitchers, the ERA calculator.
How we tested it
The formulas run against automated Node tests using the example above, which we worked out by hand: singles 92, total bases 261, OBP .364, SLG .502 and OPS .866. A second test checks that an OPS above 1 keeps its leading digit (2 home runs in 3 at-bats plus a walk gives 3.417), and a third that more extra-base hits than hits is rejected.
Frequently asked questions
Why do sacrifice flies count in OBP but sacrifice bunts do not?
That is how the official on-base percentage formula is defined: sacrifice flies are added to the denominator, sacrifice bunts are left out. A sac fly therefore lowers OBP slightly, while a sac bunt leaves it unchanged. Neither is an at-bat, so neither affects batting average or slugging.
Is OPS calculated from the rounded OBP and SLG?
It should be added from the unrounded values, which is what this calculator does. Adding the rounded figures usually gives the same answer, but it can be off by .001 now and then, so do not be surprised by a one-point difference from a site that adds rounded numbers.
Can OPS be higher than 1.000?
Yes. OBP can be up to 1.000 and slugging up to 4.000, so OPS can in theory reach 5.000. Over a full MLB season, an OPS above 1.000 is reached only by the very best hitters.
What is OPS+?
OPS+ adjusts OPS for the ballpark and the league, then scales it so that 100 is league average. A 120 OPS+ means 20% better than average. It needs league and park data, so this calculator shows plain OPS only.
Do I need to enter singles?
No. Enter total hits and the extra-base hits; singles are worked out as hits − doubles − triples − home runs and shown with the result.
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