Boneyard Tools

Sports & Recreation

Sports stat calculators for fans and players: batting average, ERA, slugging and on-base percentage, NFL passer rating, winning percentage and golf handicap, with the formulas shown.

Sports & Recreation

Arrow FOC Calculator

Calculate arrow front of center balance from arrow length and balance point. Get FOC percent and the physical center instantly. Free and private.

Sports & Recreation

Arrow Kinetic Energy Calculator

Calculate arrow kinetic energy and momentum from arrow weight and speed. Get foot pounds and slug feet per second instantly. Free, fast and private.

Sports & Recreation

Batting Average Calculator

Calculate a baseball batting average from hits and at bats. Get the decimal value and the standard .XXX display instantly. Free, fast and private.

Sports & Recreation

Climbing Grade Converter

Convert rock climbing grades between YDS, French, UIAA, V scale and Font. Route and boulder tables with clear, approximate cross references.

Sports & Recreation

Climbing Rope Length Calculator

Work out the rope length you need to top rope, lower or rappel a route. Get the rope needed plus a recommended length with a safety margin.

Sports & Recreation

Draw Length Calculator

Estimate your archery draw length from arm span or height using the standard AMO method. Get a starting draw length in inches. Free, fast and private.

Sports & Recreation

ERA Calculator

Calculate a pitcher's earned run average from earned runs and innings pitched. Supports custom game length. Free, fast and private ERA calculator.

Sports & Recreation

Fall Factor Calculator

Calculate climbing fall factor from fall distance and rope paid out. See the severity band and why fall factor, not distance, drives the force.

Sports & Recreation

Golf Handicap Calculator

Calculate golf score differentials and a handicap index from your rounds. Enter score, course rating and slope to get the WHS-style result. Free and private.

Sports & Recreation

MOA Adjustment Calculator

Convert minute of angle to inches at any distance and find the scope clicks needed. Uses true MOA of 1.047 inches at 100 yards. Free and private.

Sports & Recreation

Passer Rating Calculator

Calculate NFL passer rating from completions, attempts, yards, touchdowns and interceptions. See each component and the final rating. Free and private.

Sports & Recreation

Slugging Percentage Calculator

Calculate slugging percentage and OPS from a hitting line. Enter at bats, singles, doubles, triples and home runs, plus OBP for OPS. Free and private.

Sports & Recreation

Winning Percentage Calculator

Calculate a team's winning percentage from wins, losses and ties. Ties count as half a win, shown as a clean .XXX value. Free, fast and private.