I am developing an app for running and I can't find precise formulas for calories burned while running. I need a various formulas based on gender, age, height, weight, distance, time and so on. Any accurate formulas would be a great help for me.
There aren't any accurate equations, without data from an ECG and face mask based gas analyzers.
The best you can do without a true heart rate and O2 measures is to estimate a VO2max figure, and convert that into a Kcal one:
Kcal/Min ~= 5 calories * massKg * VO2 / 1000
The ACMS Running VO2max equation will give a number that's accurate within: +/-14.5% and the conversion to Kcal will multiply the error by a bit.
VO2 = 0.2 (speed) + 0.9 (speed)(fractional grade) + 3.5