Wins Above Replacement (WAR) Calculator

Estimate a baseball player’s WAR by combining offensive, defensive, and baserunning value into one easy-to-understand number.

WAR Calculator

League context

Typical MLB season ≈ 9–10 runs per win.

How much worse a replacement player is over 600 PA.

Player value (runs)

Runs above average from hitting (e.g., wRAA, linear weights).

Stolen bases, taking extra bases, avoiding outs, etc.

Defensive runs saved vs. average at the position.

Value of playing a harder/easier defensive position.

Playing time

For pitchers, you can ignore PA and use runs allowed instead.

Pitching (optional)

Runs above average from pitching (e.g., RA9, FIP-based).

Results

Player: —

Total WAR

0.0

Enter stats and click “Calculate WAR”.

Runs breakdown

  • Batting: 0.0
  • Baserunning: 0.0
  • Fielding: 0.0
  • Positional: 0.0
  • Pitching: 0.0
  • Replacement: 0.0

Totals

  • Runs above average: 0.0
  • Runs above replacement: 0.0
  • Runs per win: 10.0

Note: This is a simplified WAR model for educational and fantasy purposes. Official WAR values from FanGraphs or Baseball-Reference use more detailed components.

What is WAR (Wins Above Replacement)?

WAR, or Wins Above Replacement, is an all-in-one baseball statistic that estimates how many wins a player adds to his team compared to a freely available “replacement-level” player (a typical bench player or minor-league call-up).

A WAR of 5.0 means the player is worth about five extra wins to his team over the course of a season compared with a replacement-level player at the same position.

WAR formula used in this calculator

There are multiple official WAR implementations (FanGraphs WAR, Baseball-Reference WAR, etc.). This calculator uses a transparent, simplified model:

Step 1 – Runs above average (RAA)

\[ RAA = R_{\text{bat}} + R_{\text{br}} + R_{\text{field}} + R_{\text{pos}} + R_{\text{pit}} \]

Step 2 – Replacement runs

\[ R_{\text{rep}} = \text{ReplacementRunsPer600} \times \frac{\text{PA}}{600} \]

Step 3 – Runs above replacement (RAR)

\[ RAR = RAA + R_{\text{rep}} \]

Step 4 – Convert runs to wins (WAR)

\[ WAR = \frac{RAR}{\text{RunsPerWin}} \]

For pitchers, you can enter pitching runs (Rpit) and innings pitched instead of plate appearances. In that case, you can still treat replacement runs as scaled by innings or by a typical starter/reliever workload.

Typical WAR scale

  • < 0 WAR – Below replacement level
  • 0–1 WAR – Bench player / up-and-down role
  • 1–2 WAR – Role player / low-end regular
  • 2–3 WAR – Solid starter
  • 3–5 WAR – All-Star level
  • 5–7 WAR – MVP candidate
  • > 7 WAR – MVP / historic season

How to use the WAR calculator

  1. Set league context: choose Runs per win (usually 9–10) and replacement runs per 600 PA (commonly 18–22).
  2. Enter player runs:
    • Batting runs – from wRAA, linear weights, or your own model.
    • Baserunning runs – stolen bases, extra bases, outs on bases.
    • Fielding runs – defensive metrics like DRS or UZR.
    • Positional adjustment – value of playing C/SS/CF vs 1B/DH, etc.
    • Pitching runs – for pitchers, runs above average allowed or FIP-based runs.
  3. Enter playing time: plate appearances (for hitters) or innings pitched (for pitchers).
  4. Click “Calculate WAR” to see:
    • Runs above average (RAA)
    • Runs above replacement (RAR)
    • Total WAR and a qualitative label (bench, starter, All-Star, etc.)

Example: 5-WAR position player

Suppose a full-time center fielder has:

  • Rbat = +30 runs
  • Rbr = +5 runs
  • Rfield = +10 runs
  • Rpos = +5 runs (CF is a demanding position)
  • PA = 650
  • ReplacementRunsPer600 = 20, RunsPerWin = 10

Then:

  • RAA = 30 + 5 + 10 + 5 = 50 runs
  • Rrep = 20 × (650 / 600) ≈ 21.7 runs
  • RAR ≈ 71.7 runs
  • WAR ≈ 71.7 / 10 = 7.2 wins

This is an MVP-level season.

Frequently asked questions about WAR

Is this the same as FanGraphs or Baseball-Reference WAR?

No. FanGraphs (fWAR) and Baseball-Reference (bWAR) use proprietary models with many more components: park factors, league adjustments, pitcher vs. fielder responsibility for balls in play, and more. This calculator is a transparent educational approximation that lets you see how different components contribute to WAR.

Where do I get the input numbers (runs)?

  • Batting runs: from wRAA, wRC, or custom linear weights.
  • Baserunning runs: from BsR, UBR, or your own baserunning model.
  • Fielding runs: from DRS, UZR, OAA, or scouting-based estimates.
  • Pitching runs: from RA9, FIP-based runs, or expected runs allowed.

What is “replacement level” exactly?

Replacement level is the performance you’d expect from a player who is freely available: minor-league free agents, waiver claims, or bench players. Teams can acquire these players at minimal cost, so WAR measures how much better a player is than that baseline.

Can I use this for fantasy baseball?

Yes. While fantasy leagues often use different scoring categories, WAR is a useful way to compare overall real-world value and can help you identify underrated players who contribute in multiple areas (defense, baserunning, positional value).