A Free Shop Calculator for Feet, Inches and Sixteenths

Every phone has a calculator. None of them do 7 ft 3 1/2 in + 2 ft 9 7/16 in.

So you convert everything to decimal in your head, do the sum, convert back, and hope you did not fumble a sixteenth somewhere between the tape and the saw. Or you pull up a converter website, wait for it to load on one bar of signal, and dismiss two cookie banners and an ad first.

We got tired of that. So we built one and put it online for anyone to use.

Open the calculator → — free, no signup, nothing to install.

What it does

• Adds and subtracts feet, inches and fractions down to sixteenths, without ever making you convert to decimal
• Multiplies and divides — three pieces at 4 ft 7 3/8 in, or a 12 ft board split five ways
• Converts to and from millimetres, because half the hardware in a modern shop is metric
• Add it to your home screen. It opens full screen like an app, with no browser bar and no hunting for the right tab while you are holding a tape measure
• Big buttons. Sized for a thumb, and for a thumb wearing a glove

Board feet, since everyone asks

Reclaimed lumber is usually priced by the board foot, and the formula catches people out:

board feet = thickness (in) × width (in) × length (in) ÷ 144

A board 2 in thick, 12 in wide and 96 in long is 16 board feet. At $14 per board foot — what hand-hewn barn beams run here — that board is $224.

The thing to watch: board feet are a measure of volume, not area. Doubling the thickness doubles the price. A 2 in slab is twice the cost of a 1 in slab of the same face size, which surprises people standing in front of the rack.

Linear foot pricing is different again — that is just length, regardless of how thick or wide the board is. Cargo flooring is sold that way at $14 a linear foot, because every board is the same 12 in × 1.25 in.

Why we built it

We sell material by the board foot, the linear foot, the square foot and the piece. People stand in the yard doing arithmetic on the back of a receipt, and a mistake there is either a wasted trip or a board cut too short.

It costs us nothing to give the tool away, and a customer who worked out their own cut list before arriving is a customer we can actually help when they get here.

There is no signup, no email capture, and no ads. It does not send us anything. If you never buy a board from us, use it anyway.

It talks back

Every calculation lands with a line from the shop.

Measure twice. Cut once. Kerf happens. Proud by a hair? Not today. Tight as a coffin lid. The tape don’t lie.

That is not a feature so much as a side effect of building a thing for ourselves first.

Add it to your phone

On iPhone: open the calculator in Safari, tap Share, then Add to Home Screen. On Android: open it in Chrome, tap the menu, then Install app or Add to Home screen.

Either way it behaves like an app, opens full screen, and works with no connection.

Where it came from

We are Revolve Reclaimed, an architectural salvage yard at 800 S Jason St in Denver — reclaimed beams, boxcar and trailer flooring, live-edge slabs, coal-fired steel, carpet tile and used sports turf. We built the calculator for our own shop and then realised everybody standing in a lumber yard has the same problem.

Use it. Send it to whoever on your crew keeps cutting things a sixteenth short.