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🧮 A free tool for schools

Cell Phone Ban Plan Calculator

Lockers or pouches? Here's what each one takes. 🔒

Cell phone bans are easy to announce and hard to run. Put in your numbers and this works out how much equipment you'd need to get everybody through by the final bell.

This isn't a survey of what other schools bought. It's a queueing formula: you supply the numbers, it does the math. See the formulas →

It comes from a research paper, Phones Away, but Where?, which works out what a cell phone ban costs a school to operate.

1. Which one? 🤷

Splitting by grade? Run it twice — once for each group.

2. Your numbers ✏️

Estimates are fine. Everything updates as you type.

Everyone on this method.

Dismissal is the tight one — a kiddo can't put it off till later.

🗄️ Lockers only

From the supplier's spec sheet. Often around 30.

Most units are narrow enough for one kiddo at a time. Raise it if yours are wide.

🧲 Pouches only

Can any student unlock at any dock?

3. What you'd need 🧮

🗄️

Lockers

locker units

Served at once
Compartments
Everyone done in
Average kiddo waits

↔️

Compared side by side

Know what fits? 📏

Pace out your hallway, then see how long it would take.

Everyone would be done in

🤔

Why lockers need more than pouches

A locker belongs to one kiddo. A dock is shared. That means lockers need more places to serve kiddos at once for the same wait. The math is there, and so is everything this calculator assumes.

Read the reasoning →
💌

About this calculator

This calculator was built by Samantha Keppler — former high school teacher, PhD engineer, and professor of operations at the University of Michigan. Get in touch with feedback or your cell phone ban implementation stories. She'd love to hear from you!

Get in touch →

Or leave a voicemail at (313) 306-7476.