Public beta · free · no account

Design a watch movement in your browser.

Standards library, 52 calculators, gear-train designer, simulation with real escapement dynamics. NIHS-correct geometry, values you can trace, DXF your CAM reads. Free while in beta — at the bench and in your pocket.

Install on your device Works offline, opens like a desktop app.

It opens in your browser first — then install it in one gesture. On your device:

iPhone or iPad: tap the Share button, then “Add to Home Screen”.
Android (Chrome): open the ⋮ menu, then “Install app” or “Add to Home screen”.
Computer (Chrome or Edge): click the install icon at the end of the address bar, or the ⋮ menu → “Install Horolator”.

Open Horolator now →

Open in your browser Nothing to install — start right now.

Read the 10-minute guide →

No account required. Free while in beta.

Horolator Designer with a five-arbor going train on the canvas, assembly tree at left, and a panel confirming beat rate 21,600 of 21,600 vph with per-mesh modules stepping down toward the escapement.

Designer: an auto-suggested going train hitting 21,600 vph, with live collision checks and per-mesh module verification.

87NIHS standard entries
52calculators
17languages
DXF· SVG · STEP export

Look it up. Prove it. Cut it.

A movement begins as arithmetic — beat rate, train ratios, module, mainspring torque — scattered across standards, worked examples and workshop habit. Horolator keeps that arithmetic in one place, shows where every value comes from, and carries the result all the way to geometry a machine can cut.

01
Look it up
The Library holds 87 browsable NIHS standard entries — pivot fits, threads, jewels, screws, gear trains, barrels, balances and hairsprings, shock absorbers, cases, lubrication — with a unit converter for millimetres, inches and lignes, and PDF export of the page you're on.
02
Prove it
52 calculators cover the whole chain from beat rate to detent escapement geometry. Each one draws its schematic to scale from your values, marks which inputs are decisions and which are computed, and explains itself in a collapsed “How to use”.
03
Draw it, run it, export it
Designer generates horologically correct NIHS wheels and lays out the train with collision checks. Simulate drives it from the mainspring you actually chose — amplitude and reserve solved with real escapement dynamics. Export DXF, SVG, STEP or a PDF technical drawing.

The four sections

Horolator is organised the way the work is. Everything below ships today, free, in the public beta.

Designer

Wheels you can machine

The gear generator produces the Swiss ogival wheel-and-pinion form to NIHS 20-02 / 20-10 — with NIHS 20-25 corrected epicycloidal and ISO 53:1998 involute profiles alongside — as first-class parts, not pictures. Auto-suggest a going train, chain power interactively, check collisions and caliber fit, see the movement in a 2.5D section view, and pick a real catalogue mainspring with amplitude and reserve verdicts solved by the same dynamics as Simulate.

Features → Designer

One press of “Auto-suggest train”: tooth counts, pinion leaves and modules for the whole chain, solved for a 21,600 vph target.

Simulate

Watch the forces, not an animation

The simulation derives every rate from the project's own tooth counts and drives the train from the mainspring you chose in Designer. Watch tooth forces, pivot loads and power flow as live layers on the canvas; wind the barrel down and see amplitude follow the spring — solved with Runge–Kutta escapement dynamics through unlocking, impulse and free swing. The Spring lab analyses hand-drawn blade springs with an in-browser finite-element engine.

Features → Simulate

Simulate running at 1×: the going train ticks through the escapement while live force arrows show tooth loads from barrel to escape wheel.

Library

The standards, made visual

Pivot fits, threads, jewel tolerances, screw designations, gear-train geometry, barrel dimensions, balance and hairspring tables, shock absorbers, case and crown interfaces, dials, hands, lubrication — 87 NIHS standard entries, browsable and searchable, each citing its standard. Any page exports as a PDF, and the gear tool previews a single wheel and exports it as DXF.

Features → Library

Horolator Library: a searchable grid of NIHS standard categories — pivot fits, threads, barrel and spring, gear train, balance and hairspring, jewels, shock absorbers, screws, case and crown, lubrication.

Calculator

Every number defends itself

52 calculators, from beat rate and gear mesh to mainspring energy, pendulums, torsion oscillators and the classical escapements — Swiss lever, cylinder, detent, Robin, verge. Inputs are marked as decisions or safe defaults, outputs as computed; the schematic redraws to scale from your values; and every card opens with a “How to use” that teaches the tool, not just labels it.

Features → Calculator

An open Horolator calculator, Gear mesh, showing a to-scale diagram of two meshing pitch circles with the centre distance dimensioned.

Beta means: help us break it.

Horolator is in free public beta: every tool is open, nothing is locked, and no account is needed — signing in only adds cloud sync between your devices. We won't promise “free forever”, because honest software doesn't promise what it can't know. We will promise this: your exports are standard DXF, SVG and STEP files, yours to keep, whatever happens to pricing.

What the beta asks in return is scrutiny. If a value looks wrong, a table disagrees with your workshop experience, or a layout breaks on your phone — press Feedback inside the app. It attaches the app version and the view you were on, shows you exactly what it collected before sending, and goes straight to the watchmaker who builds this.

Open the beta and kick the tyres

Fair questions

Is Horolator really free?

Yes — during the public beta everything is free and unlocked, with no account required. Future pricing is undecided; we deliberately don't promise “free forever”. Whatever happens, your exported files are open formats (DXF, SVG, STEP, PDF) and remain yours.

Do I need to install anything?

No. Horolator runs in the browser on desktop, tablet and phone. If you'd like an app icon and offline use, you can install it to your device in a couple of taps — the front page shows how, per device.

Where do the numbers come from?

From published standards and classical horological theory: NIHS tables for fits, threads, jewels, gears, barrels, balances and more, plus closed-form mechanics for springs, oscillators and trains. Every table cites its standard and every calculator shows its formula — the app never invents numbers, and where a source is missing it says so instead of guessing.

Is the simulation real physics or a looping animation?

Real physics, first-order and labelled as such. Rates come from your tooth counts; torque comes from the mainspring you picked, declining over the wind; amplitude is solved from the escapement's equations of motion (a Runge–Kutta integration through unlocking, impulse and free swing) — so the movement stops when the swing can no longer clear the unlocking window, not when a timer runs out.

Can I manufacture parts from Horolator's output?

The DXF exports are built from true LINE and ARC entities — not polyline approximations — so CAM software and Fusion 360 read them cleanly. The Spring lab also exports STEP. As with any tooling, verify dimensions against your own process before cutting metal; it's a beta, and telling us what you find is the fastest way to make it trustworthy.

Where does my design data live?

On your device, in the browser's local storage. If you sign in, projects sync through the cloud so you can move between phone and desktop — sign-in adds nothing else, and you can use everything without it.

What languages does it speak?

The interface ships in 17 languages, including English, German, Spanish, Italian, Portuguese, Japanese, Chinese (simplified and traditional), Korean, Russian, Ukrainian, Polish, Czech, Dutch, Swedish, Turkish and Finnish. French is being finished.

The tools are on the table.

No sign-up, no download, no trial clock. Look up a fit, run a train, export a wheel.