Baseball OPS+ Calculator (Park-Adjusted)
Turn on-base and slugging into OPS+, the park- and league-adjusted metric where 100 is league average and higher is better.
How it works
OPS+ = 100 × (OBP ÷ lgOBP + SLG ÷ lgSLG − 1) ÷ (ParkFactor ÷ 100)
OPS+ rescales a hitter’s on-base and slugging against the league so that 100 is exactly average and every point above or below is a percentage point of offense. Dividing by the park factor strips out the boost a hitter gets from a bandbox or the penalty from a pitcher’s park, making players comparable across ballparks. A 130 OPS+ means 30% better than league-average offense.
Worked example
With a .360 OBP and .500 SLG against a league .320/.410 in a neutral park (100): 100 × (.360/.320 + .500/.410 − 1) ÷ 1 = 100 × (1.125 + 1.220 − 1) = 134 OPS+.
Sources: OPS+ — Wikipedia
Frequently asked questions
What does an OPS+ of 100 mean?
100 is league average by definition. A 150 OPS+ is 50% better than average offense; a 75 OPS+ is 25% worse. This centering is what makes OPS+ easier to read than raw OPS.
How does the park factor work?
A park factor above 100 marks a hitter-friendly park, so dividing by it lowers a hitter’s OPS+ to remove that help; a factor below 100 (a pitcher’s park) raises it. A neutral park of 100 leaves the number unchanged.
Is this the exact Baseball-Reference formula?
It is the standard published OPS+ formula. Baseball-Reference applies slightly more elaborate league and park adjustments, so real published values can differ by a few points, but the method and scale are the same.
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This calculator is for educational purposes. Double-check important results before acting on them.