Math & Science Calculators

A weighted average assigns each value a weight reflecting its relative importance before computing the mean. Use it whenever different values should not count equally, such as exam scores worth different percentages of a grade, investment returns from positions of different sizes, or ratings from surveys with different sample counts. The formula is: Sum of (value × weight) divided by sum of weights.

The midpoint formula is M = ((x1+x2)/2, (y1+y2)/2). Add the two x-coordinates and divide by 2 to get the midpoint x; do the same for y. Our midpoint calculator also returns the distance between the two points using the Pythagorean theorem, and the slope of the line segment, so you get all three related values in a single calculation.

ERA (Earned Run Average) is the most widely used pitching statistic. It equals (Earned Runs ÷ Innings Pitched) × 9, representing the average number of earned runs a pitcher would allow over a complete 9-inning game. An ERA below 3.00 is excellent in Major League Baseball. An ERA above 5.00 is generally considered poor. ERA excludes unearned runs caused by fielding errors.

Fat-Free Mass Index (FFMI) measures muscle mass relative to height, similar to BMI but isolating lean body mass. It is calculated as lean mass in kilograms divided by height in meters squared. FFMI values above 25 are considered the approximate natural limit for most adult males without performance-enhancing substances, making it a useful benchmark in fitness and sports medicine contexts.