Updated

A Philadelphia father put the city's signature sandwich to use in a whole new way: measuring his baby's size in cheesesteaks.

Philly.com reports Thursday that computer programmer Brad Williams used a foolproof system he calls "Cheesesteak for Scale" to measure the growth of his son during the child's first year in 2015.

e3497c1e-cheesesteak baby

Brad Williams used a foolproof system he calls "Cheesesteak for Scale" to measure the growth of his son during the child's first year in 2015. (AP)

US SOLDIER IN IRAQ HOPS 10 FLIGHTS HOME TO WITNESS DAUGHTER'S BIRTH

It started when he noticed his 2-week-old, Lucas Royce, was about the same size as a cheesesteak he'd brought home. So Williams snapped a picture of the sandwich next to his newborn and the tradition was born.

Every month for the next year Williams and his wife would buy a cheesesteak to track their growing boy.

8dd91698-cheesesteak baby

Every month for the next year Williams and his wife would buy a cheesesteak to track the growth of their son. (iStock)

FOLLOW US ON FACEBOOK FOR MORE FOX LIFESTYLE NEWS

He says babies and cheesesteaks are quite similar. He says they are warm and cuddly when wrapped up "but once you unwrap them, expect a huge mess."