🔢 WAR Calculator
Convert run-value components into Wins Above Replacement to estimate overall player value.
Use values from wRAA, wRC, or Baseball-Reference batting runs.
FanGraphs BsR or Baseball-Reference baserunning component.
Use Defensive Runs Saved, UZR, or OAA translation.
Adjust for defensive difficulty: catchers/SS positive, 1B/DH negative.
Optional: adjust for league/era differences (FanGraphs typically ~ -2).
Usually ~20 runs per 600 PA for position players, scaled to playing time.
League environment: 10 is typical, but 9.5–10.5 is common.
How to Use This Calculator
Grab Run Components
Export batting, baserunning, fielding, and positional runs from your preferred stats site.
Add Replacement Runs
Scale replacement level to playing time (~20 runs per 600 PA for hitters).
Adjust for League & Context
Optional league/park adjustments can be entered in the Rlg field.
Set Runs Per Win
Use 10 for modern MLB or a value tailored to your league run environment.
Formula
WAR = (Rbat + Rbr + Rfld + Rpos + Rlg + Rrep) ÷ Runs Per Win
WAR converts a player’s overall run contributions into wins relative to a replacement-level player. Different public models (FanGraphs fWAR, Baseball-Reference rWAR, Baseball Prospectus WARP) tweak inputs, but all share the same core concept.
Variables
- Rbat: Batting runs above average
- Rbr: Baserunning runs
- Rfld: Fielding runs
- Rpos: Positional adjustment
- Rlg: League/park adjustment
- Rrep: Runs above replacement level
- RPW: Runs required per win
Example
Player totals: Rbat 35.2, Rbr 5.1, Rfld 8.3, Rpos -5.0, Rlg -1.8, Rrep 18.7. Total runs = 60.5. Using RPW=9.9 gives WAR = 60.5 ÷ 9.9 = 6.1 wins.
Understanding WAR
Wins Above Replacement captures total value by estimating how many more wins a player provides compared to a readily available “replacement” player. It balances offense, defense, position, and playing time in a single number.
Benchmark Guide
- > 8 WAR: MVP / Cy Young level
- 5 – 7 WAR: Superstar
- 3 – 5 WAR: All-Star
- 2 – 3 WAR: Everyday starter
- 0 – 2 WAR: Role player / part-time
- < 0 WAR: Replacement level
Limitations
- Inputs vary by site; expect small differences between fWAR, rWAR, and WARP.
- Defensive metrics have noise. Use multi-year samples for reliable fielding WAR.
- Pitcher WAR uses different components (FIP or RA9). This tool focuses on position players.
Frequently Asked Questions
Where do I find these run components?
FanGraphs player pages list Batting, Baserunning, Fielding, and Positional runs. Baseball-Reference provides similar categories in the “Value” section.
What value should I use for replacement runs?
Multiply plate appearances by roughly 0.03. FanGraphs uses 20 runs per 600 PA. Adjust for the player’s playing time or Innings for pitchers/fielders.
How accurate is this WAR?
It’s an estimate. Official sites include park factors, leverage, and rounding. Expect values within a few tenths of published WAR if you match their components.
Can I use it for pitchers?
This calculator targets position players. Pitcher WAR formulas differ: FanGraphs uses FIP-based runs saved, while Baseball-Reference uses runs allowed with adjustments.
Why do runs per win change?
Run environments vary by era and league. Higher scoring environments require more runs to equal one win, so RPW creeps up slightly when offense explodes.