Scale number from range A to range B

scaleNumber.md

Sometimes we need to transfer a number from range A to range B
I wrote this in ts but you can easily change it to your preferred language
hope this save your time.

type Scale = (
  number: number,
  from: [number, number],
  to: [number, number]
) => number;

const scale: Scale = (number, from, to) => {
  const stepCost = (to[1] - to[0]) / (from[1] - from[0]);
  const startOffset = number - from[0];
  const newNumber = startOffset * stepCost + to[0];
  return newNumber;
};

scale(5, [0, 10], [0, 100]); // return: 50