Pricing

Free + Pro monthly or annual plans

Free tier

Straight stair + stringer workflows

Exports

PDF blueprints and CSV material lists

Privacy

No analytics, ads, or tracking permissions

Utilities

Productivity

Free with in-app purchases

Stairs 3D: Framing Calculator

Stairs 3D is a field-ready stair framing calculator that solves stair geometry instantly, lets users inspect the result in 3D, and packages the outcome into blueprints, cut lists, PDFs, and CSVs without requiring an account or network connection.

iOSDownload on theStairs 3D: Framing CalculatorFree with in-app purchases · iOS 17.6 or laterOpen

View developer profile Browse all apps

iOS 17.6 or later5 MBVersion 1.0.0

Built for

The users and project contexts this app is designed to serve.

Carpenters and contractors laying out straight, landing, and turning stairs.

Deck builders who need dependable stringer geometry and material counts.

Serious DIY builders who want field-ready stair documentation on iPhone or iPad.

Why teams choose it

Shared advantages carried through the mobile workflow.

Entire workflow stays offline and on device.

Supports imperial fractions and metric units with configurable precision.

Combines live calculation, 3D review, and blueprint output in one app.

Core capabilities

The main workflow coverage called out in the App Store listing.

Instantly solve rise per step, tread depth, stair angle, stringer length, and cut patterns.

Model straight stairs and stringer layouts in the free tier.

Upgrade to landing, L-shaped, U-shaped, and spiral stair builders in Pro.

Inspect each stair with a rotatable 3D model and a component inspector for cut dimensions.

Generate annotated 2D plan and elevation views for shop or field use.

Outputs and handoff

What users can review, package, and share after planning.

Auto-generated material cut lists for takeoff.

Printable PDF blueprints for field, client, or shop use.

CSV exports for spreadsheet or procurement workflows.

Free includes

What users get before upgrading.

Straight stair calculation.

Stringer layout, 3D inspection, 2D blueprint, and project saving.

Pro unlocks

What the paid tier adds for heavier day-to-day use.

Landing, L-shaped, U-shaped, and spiral stair builders.

PDF and CSV export for deeper production workflows.

Monthly: $5.99/month · Annual: $49.99/year

Privacy and workflow ownership

What the app listing says about data handling and local control.

The app description states there are no analytics SDKs, third-party data collection, or ads.

It does not request camera, microphone, location, photo library, or tracking permissions.

App Store privacy details say the developer does not collect data from this app.

Projects and exports remain available on the device unless the user chooses to share them.

Users can keep viewing, editing, and exporting their own projects even if they cancel a plan.

The only external connection called out is the App Store for optional plan management.

Platform details

Reference details pulled from the current App Store listing.

Compatibility

iPhone, iPad, Mac with Apple silicon, and Apple Vision support via the App Store listing.

Bundle ID

com.zerothfloor.stairs

Released

March 19, 2026

Updated

March 20, 2026

Important notes

Stairs 3D is positioned as an offline-first stair workspace rather than a generic calculator.

Install Stairs 3D

Take the workflow to the field

Open the App Store listing for pricing, install, and version details, then keep the full product page close for capability and workflow context.

iOSInstall from theStairs 3D: Framing Calculator$5.99/month or $49.99/yearOpen

Quick install facts

Free with in-app purchases

iOS 17.6 or later

iPhone, iPad, Mac with Apple silicon, and Apple Vision support via the App Store listing.

Follow the full mobile lineup on the App Store

Keep track of the broader iPhone and iPad portfolio and move between roof, stair, and deck tools from the same developer profile.

Open developer page

Explore related apps

Move between the roof, stair, and deck workflows in the ZerothFloor mobile suite.

View all apps

Roof Rafter: Framing Calc

Roof framing math, diagrams, and PDF packets from iPhone or iPad.

Roof Rafter gives framers and contractors a roof-specific workspace for calculating rafter geometry, reviewing annotated 2D and 3D outputs, and turning field inputs into organized job packets without doing roof math by hand.

Open app page

Decks 3D: Deck Builder

Framing-first deck plans, 3D review, and local build documents.

Decks 3D helps contractors, designers, and builders plan deck projects with deck-specific framing controls, live 2D and 3D review, material outputs, and on-device export workflows instead of relying on generic home design software.

Open app page