My World Tools

Permutations & Combinations

Enter n (total items) and r (chosen items) to see both formulas calculated.

Permutations (nPr)

720

Combinations (nCr)

120

Permutations: how many ways to arrange 3 of 10 items in order (e.g. 1st/2nd/3rd place)

Combinations: how many different groups of 3 you can pick from 10 items, where order doesn't matter

You might also find these useful

Free Fall: Vacuum vs. Air ResistanceCompare falling in a vacuum against falling with air resistance and see the terminal velocity.
Orbital MechanicsAdjust a satellite's altitude and see how its orbital speed and period change.
Integral VisualizerSee the area under a curve build up as a sum of rectangles, approximating the integral.
Advertisement
Molar Mass CalculatorEnter a chemical formula like Ca(OH)2 to compute its molar mass and element breakdown.
Poisson DistributionAdjust the average event rate and see how the Poisson distribution shape changes.
Moon Phase CalendarSee the moon's phase and illumination for any date, calculated on the spot.
Advertisement