Free Blueprint Calculator — FAQ

Upload your blueprint image or PDF, enter the scale from the title block (or calibrate using a known dimension), then trace the area using the Polygon or Rectangle tool. Square footage is calculated automatically as you draw.

For a full walkthrough see our step-by-step guide.

The calculator accepts PNG, JPG, GIF, WebP, and PDF files. PDF blueprints are automatically rendered — the first page is converted to an image for tracing.

DIY-friendly: You don't need professional blueprints! You can upload hand-drawn sketches or photos of your space. Just make sure the image is clear and includes a reference measurement (like a door width or known dimension) so you can set the scale accurately.

If your PDF has multiple pages and the plan you need is not on page 1, extract or print just that page as a separate PDF first.

Yes. You can trace as many sections as you need on the same blueprint. Each shape is given a label (e.g. "Main Deck", "Hot Tub Area") and listed individually in the Area Breakdown table. The results show subtotals per section and a combined net total.

There are three ways to close a polygon:

• Click or tap the first point again (highlighted in blue) — this closes the shape automatically
• Double-click anywhere on the canvas
• Tap the Close Shape button in the sidebar

On mobile, the first-point tap target is enlarged to make it easier to close shapes with your finger.

While drawing a polygon, use the Undo button to remove the last point placed. To delete all shapes and start over, use the Clear All button.

Yes. The Copy Report button copies a plain-text summary to your clipboard (area breakdown, waste factor, and order total). The Print button opens a print-ready page with the annotated blueprint image and a results table.

After tracing your blueprint, hand-drawn sketch, or photo and entering material specifications (like paver size, concrete thickness, or paint coverage), the calculator generates an instant shopping list showing exactly how much material to order. The results include net quantities and order quantities with waste factor, ready to use at Home Depot, Lowe's, or any supplier.

Use the Copy Report button to copy the material list to your clipboard, or Print to get a formatted report you can bring with you to the store.

In the Set Blueprint Scale section, select "Enter scale manually". Type 1/8 in the Blueprint Distance field and 1 in the Real-World Distance field. Set units to inches and feet. The app converts fractions to decimals automatically.

The most common scales for residential construction drawings include:

• 1/8″ = 1’ (1:96) — typical for plan sets showing full house layouts
• 1/4″ = 1’ (1:48) — common for detail drawings and deck plans
• 3/16″ = 1’ (1:64) — used in some residential plan sets
• 1″ = 10’ — sometimes used for site plans

Look for the scale notation in the title block, usually in the lower right corner of the drawing sheet.

Use the Calibrate from blueprint option. Switch scale type, draw a line over any element on the plan whose real length you know (a wall, a door opening, a property line), then enter the actual length. The app calculates the correct scale from that measurement.

A few things to check:

• Make sure the scale fraction is entered correctly (e.g. 1/8 in blueprint, 1 in real-world, units: inches and feet)
• Check that the units match — blueprint distance in inches, real-world distance in feet is the most common setup
• If you used calibration, make sure you drew the line over the correct element and entered the right real-world length
• Compare a simple known dimension on the drawing (e.g. a 12-foot wall) against the calculator's output for a rectangle traced over that wall

Yes. The calculator is fully mobile-responsive and supports touch drawing on both iOS and Android. Tap to add polygon points, drag to draw rectangles, and use two-finger pinch to zoom.

On iPhone (Safari): Tap the Share button at the bottom of the browser, then tap "Add to Home Screen". The app will install with the LeapfrogIQ frog icon.

On Android (Chrome): Tap the three-dot menu and select "Add to Home Screen" or "Install App". If Chrome detects the PWA, an install banner may appear automatically.

Once installed, it opens without browser UI in a dedicated window.

Yes. Two-finger pinch zoom is supported on iOS and Android. You can also use the +/− buttons in the lower-right corner of the canvas to zoom in and out.

The core calculator works offline once the page has been loaded. If you install the app to your home screen (PWA), the app is cached and available without a network connection. Note that PDF.js (for PDF rendering) requires an initial connection to load.

No. All image processing and calculations happen entirely in your browser. Your blueprint image is never uploaded to any server, and it is not stored beyond your current session. When you close or refresh the tab, the image is gone.

No. The app does not require an account, login, or any personal information. We do not collect names, emails, IP-linked user data, or measurement data.

See our Privacy Policy for full details.

We use anonymous usage analytics to understand how the app is used and where to focus improvements (e.g. which tools are used most, where users drop off). No personally identifiable information is linked to these events.

Our Privacy Policy describes this in detail.

The Blueprint Construction Calculator is built and maintained by LeapfrogIQ, a software company focused on practical tools for contractors, healthcare, and professional workflows. The project was created by Mat Robie.

Learn more on the About page.

Yes, the core calculator is free to use with no signup required. Future versions may introduce optional premium features for saving projects, advanced material estimates, and contractor workflow tools.

We are actively building additional calculators including concrete slab, tile coverage, fence material, and patio area tools. They share the same blueprint measurement engine as the deck calculator.

Have a specific request? Let us know.

Use the Contact page to send feedback, report issues, or suggest features. We read all submissions.