densityBasedPercentage.js

import { Dimensions, Platform, PixelRatio } from 'react-native';

const { width, height } = Dimensions.get('window');

const getWidthFromDP = (widthPercentage) => {
  const percentageDesired = parseFloat(widthPercentage);
  const widthPercentageToDP = PixelRatio.roundToNearestPixel((width * percentageDesired) / 100);

  return widthPercentageToDP;
};

const getHeightFromDP = (heightPercentage) => {
  const percentageDesired = parseFloat(heightPercentage);
  const heightPercentageToDP = PixelRatio.roundToNearestPixel((height * percentageDesired) / 100);

  return heightPercentageToDP;
};

// USAGE

marginLeft: getWidthFromDP('12%');
fontSize: getHeightFromDP('1%');