Angular 2 data size formatter pipe

data-size.pipe.ts

import { Pipe, PipeTransform } from '@angular/core';

@Pipe({
  name: 'dataSize'
})
export class DataSize implements PipeTransform {

  private suffixes = ['KB', 'MB', 'GB', 'TB', 'EB', 'YB'];
  
  // Specified input units (MB default (1000000))
  transform(num: number, start = 1000000): any {
    const idx0 = ~~(Math.log(start) / Math.log(1000));
    const idx1 = ~~(Math.log(num) / Math.log(1000));

    return `${(num / Math.pow(1000, idx1)).toFixed(1)} ${this.suffixes[idx0 + idx1 - 1]}`;
  }
}