Use the web app on a desktop or Android phone, or download Build Specs for iPhone. Sign in with the same account to keep supported saved stair calculations and gas and water layouts together.
01
Start anywhere
Check a run, lay out stairs, or build a planner in the browser or on iPhone.
02
Save your work
Save a stair calculation or gas and water planner layout to your account, then open it on your other device.
03
One account, shared Pro access
Link your subscription to your Build Specs account on iPhone, then use the same account on the web. A web subscription works on iPhone with the same sign-in, too.
SIMPLE ACCESS
Pro when you need more than a quick answer.
On the web, your first signed-in tool use starts a one-time 15-minute preview. On iPhone, version 1.0.7 and later includes a 15-minute first-launch preview; earlier versions include 10 minutes. Pro keeps the tools available after your preview ends.
BEST VALUE
Annual
$39.99 / year
Eligible new subscribers get seven days free, then $39.99 per year.
Prices shown are in U.S. dollars. Subscriptions renew automatically unless canceled. Local pricing, taxes, and trial eligibility are shown before purchase. Manage or cancel through the platform where you subscribed. Link your subscription to the same Build Specs account to share active Pro access between iPhone and the web.
SEE IT AT WORK
A closer look at the stair calculator.
Watch a quick walkthrough of the layout details that turn a total rise into a cuttable stringer plan.
