I saw a suggestion to use an old plank of wood to hang on the wall and mark heights onto that. Then, when you leave that home, you can take the plank of wood with you. I thought it was a beautiful idea!
However, I generally don't have old wood laying around, and I don't have a saw to easy cut through a tossed aside piece of wood. So searching the internet, I found people who sold pre-marked wooden growth charts for, on average, $75...a bit above my available budget.
So yesterday, I took the bull by the horns, packed the kids in the van, and headed to Lowes. They have pre-cut wood, you know. And wood stain to make the wood look weathered and worn. And hangers. I knew all this, but for some reason I thought it would be a lot more expensive than it was. As it turned out, the wood, the stain, and the hangers, as well as vinyl numbers and a foam brush, cost less than $25.
This is a 1x6x6 pinewood board stained with one coat of Rustoleum's Provincial stain (don't skimp on the wood - this is a "hang in your house until you die" type of piece, beautiful wood matters). I marked out the dashes with permanent marker for every inch, making the 6" and 12" marks longer. I carefully cut out the black 2" vinyl numbers (they came on a white background) and stuck them on. Then I hung the board 6" off the ground (the marks go from 6" to 6'6" - hoping Benjamin doesn't end up a giant!).
The children's heights are marked in colored permanent marker. I can go back to their medical records and pull their heights to mark on the board. And this board can go with us wherever we live!