AR Sundial Builder - an augmented reality app for Android that guides you to build a real, working sundial.

Building a working sundial is hard.
We do the math for you.

AR Sundial Builder walks you through creating all seven types of sundial: horizontal, vertical, equatorial, polar, armillary, analemmatic, and reflected-ceiling.

Our augmented reality tools let you calibrate a sundial based on the sun’s position at your location. You simply decide where you want your sundial to be.

Use the finished AR sundial as a template, download the measurements, and build a working dial in your environment using your chosen materials.

Guided AR Build
True-North Alignment
Off-Grid Latitude Calculation
Real Sundial Math

I Why AR?

A visual template for your real-world build.

Every step draws its geometry straight onto the live camera - the base circle, the gnomon, the hour lines and their labels - so you can see exactly where each mark lands before you commit it.

That is what makes augmented reality the right tool for the job. A sundial is defined by its exact size, its spot on the ground, and its orientation to the sky - things a flat paper plan can never show you in place. AR renders the finished dial at true scale on the real surface, so you can walk around it, check the shadow has a clear path, and catch any mistake before you build.

II The Build

Download the plans. Build at your convenience.

Every finished dial comes with a downloadable set of build plans - the exact dial radius and diameter, the gnomon angle for your latitude, a table of every hour-line angle, and a step-by-step guide to marking it all out by hand.

And the AR overlay stays with you as a visual template: it shows exactly where the gnomon, hour lines, and north marker fall, so you can confirm the placement of every element against the real surface before you commit it.

Build it however suits you - scratched into the sand at the beach with a stick, or cut from timber, stone, or metal in a workshop with your chosen materials.

III The Math

The math a sundial actually needs.

Hour lines, gnomon angle, and substyle geometry all follow established British Sundial Society / Waugh conventions - the same references used to lay out dials by hand.

θ = arctan(H / S)

Gnomon angle = φ

The gnomon’s style height is set to your latitude, and every hour-line angle is computed to stay precise across the whole day. Each finished dial is checked against true solar noon.

The math is explained at every step, so you can follow the exact formulas - the sun’s hour angle, its azimuth and declination, the substyle geometry, and the magnetic-declination correction that resolves true north.

A family on a beach at golden hour building a sundial in the sand — a leaning stick as the gnomon and stones marking the hours around a drawn circle — checking a phone as they work.

IV 7 Sundial Types

Seven ways to tell the time by the sun.

Every type is a complete augmented reality build. Start with the classic horizontal dial, then unlock any of the others - individually or as a full set.

Horizontal

The classic garden dial. Simple to lay out and read anywhere.

Vertical

Wall-mounted for sunny patios, garden walls, and facades.

Equatorial

Tilted to your latitude, with evenly-spaced hour markings.

Polar

Parallel hour lines, evenly spaced. Minimalist and quick to read.

Armillary

A sculptural sphere of rings - a striking garden showpiece.

Analemmatic

A walk-on dial where you stand in as the gnomon.

Reflected Ceiling

An indoor dial a mirror projects onto your ceiling.

A camper at a remote mountain campsite using a stick planted in the ground and rocks placed along its shadow to track the sun and find direction, no network required.

V Off-Grid Tools

Find your latitude by solar noon, off-network, off-grid.

For enthusiasts and the curious, AR Sundial Builder also guides you through the ancient stick & shadow method in augmented reality - locate true north, find solar noon, and discover your latitude without a network connection.

Find North & Solar Noon uses a stick’s shadow over time to locate true north and the exact moment of solar noon.

Find Latitude reads the noon shadow’s length against today’s date to estimate where you are on the globe.

True North AR captures the shadow live - no cell towers, no satellites, no connection. Augmented reality and battery power are all it takes to self-locate anywhere on Earth.

A high-school teacher holding a phone showing the app's sundial view while explaining a real sundial on the table to a few students, with sundial geometry sketched on the whiteboard behind them.

VI Education

Built to teach, not just to build.

Every step of every dial type comes with a plain-language explanation, the underlying math, and links to go deeper - so you finish understanding the instrument, not just following prompts.

Plain language

Detailed explanations

Every action in the build is explained as you go - what you are doing, why it matters, and how it shapes the finished dial. No black boxes, no blind taps.

Real geometry

The math, shown

Behind each step sits the actual math: the formulas, the hour-line angles, and how your latitude sets the gnomon - laid out so you can follow it or check it yourself.

Deep-dive resources

Every dial type links out to trusted references and reading - from BSS / Waugh conventions to solar geometry - so the learning carries on well past the build.