Calculate AVG, SLG, ERA, or WHIP
Choose a mode, enter the displayed fields, and select Calculate. The result shows the selected baseball metrics, the formula used, and a plain-text result that you can copy or download.
How to use the calculator
- Choose Batting (AVG & SLG) or Pitching (ERA & WHIP).
- Enter the fields for that mode. In pitching mode, use Full innings pitched and Extra outs (0, 1, or 2).
- Select Calculate.
- Review Result, Formula used, and the table. Batting lists the entered values and calculated values. Pitching also lists total outs and decimal innings.
- Select Copy result for plain text or Download result (.txt) to save a text file.
Switching modes hides the current result and clears the displayed error. Each mode has its own Reset button.
Enter innings pitched correctly
The digit after the decimal in baseball notation counts outs, not tenths of an inning. Enter the full innings and the extra outs separately: 6.1 means 6 full innings and 1 out, or 19 total outs. Baseball notation 6.1 therefore means 6 1/3 innings, while decimal 6.1 means 6.1 innings. The calculator uses Total outs = Full innings × 3 + Extra outs, then Decimal innings = Total outs ÷ 3.
Formulas and displayed values
AVG = Hits ÷ At-batsSLG = Total bases ÷ At-batsERA = (Earned runs ÷ Innings pitched) × Innings per gameWHIP = (Walks allowed + Hits allowed) ÷ Innings pitched
AVG and SLG display to three decimal places without a leading zero, such as .275. ERA and WHIP display to two decimal places. Innings per game affects ERA only; WHIP remains a per-inning rate.
Validation, Reset, and result actions
- Counting inputs must be whole numbers of 0 or more.
- At-bats must be greater than 0.
- Hits cannot exceed At-bats. Total bases must be between Hits and four times Hits.
- Full innings pitched and Extra outs (0, 1, or 2) together must represent more than 0 outs.
- Innings per game (ERA only) must be greater than 0.
Selecting Reset clears that mode's inputs, hides the result, and clears errors. Pitching Reset also restores Extra outs (0, 1, or 2) to 0 and Innings per game (ERA only) to 9. The batting download is named baseball-batting-result.txt; the pitching download is named baseball-pitching-result.txt.
Limitations and calculation scope
The calculator uses the numbers you enter. It does not fetch player, team, or league records, apply a specific league's official rulebook or qualification rules, or calculate advanced sabermetric statistics. Calculator values are processed in the browser by the calculator script; this does not describe other page features or network activity.
Innings per game accepts any positive numeric value. The calculation uses the value entered, but the result table and downloaded text format it with zero decimal places.
Frequently Asked Questions
How is batting average calculated?
Batting average (AVG) = Hits / At-bats, conventionally shown to three decimal places without the leading zero, such as .275.
How is slugging percentage calculated?
Slugging percentage (SLG) = Total bases / At-bats, where total bases counts 1 for a single, 2 for a double, 3 for a triple, and 4 for a home run, also shown to three decimal places.
How is ERA calculated?
ERA = (Earned runs / Innings pitched) x Innings per game. Innings per game defaults to 9, the standard for Major League Baseball, but is editable for leagues that use a different game length.
How is WHIP calculated?
WHIP (walks plus hits per inning pitched) = (Walks allowed + Hits allowed) / Innings pitched. Unlike ERA, WHIP is not scaled by an innings-per-game value - it is always a per-inning rate.
Why do I enter innings pitched as two separate fields instead of a decimal?
Baseball innings pitched is conventionally written like 6.1 or 6.2, where the digit after the decimal point means outs (1 or 2), not tenths of an inning. Entering full innings and extra outs separately avoids treating 6.1 as 6.1 decimal innings.
Does this tool pull live player or league statistics?
No. It does not fetch any player, team, or league record, and it does not apply any specific league's official rulebook or advanced sabermetric formula. You supply the raw counting stats; the calculator only does the arithmetic for AVG, SLG, ERA, and WHIP.