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Grainsway

Name: Grainsway: Wood Movement Calc
Price: 1.99 USD

Wood Movement Calculator for Android

Get it onGoogle Play

Price: One-time purchase $1.99. No ads, no subscription, no in-app purchases.

Grainsway works out how much solid wood will move, offline. Enter a board's width, species and sawing orientation, then the moisture change it will see - either a start and end moisture content, or room humidity and temperature at each end - and see exactly how much it will swell or shrink, in millimetres or inches. Then turn that into the gap, groove or slot a panel, breadboard end or tabletop fastener needs, so it never splits or shows a gap.

Features

Calculate

Board width (mm or in, inch fractions accepted), from 68 built-in species or your own custom species
Sawing orientation: flat-sawn, quarter-sawn or rift-sawn, each with its own movement coefficient
Moisture: type a start and end moisture content, or room relative humidity and temperature (°C or °F) - converted to equilibrium moisture content with the Hailwood-Horrobin equation the Wood Handbook uses
Movement and end width, or a full winter-to-summer seasonal range
A warning when a result is clamped at the species' fibre saturation point, or extrapolated beyond the humidity table

Allowances

Floating panel: the groove depth and the gap per side, so the panel never bursts the frame in summer or shows a gap in winter
Breadboard end: the elongated peg slot each outer peg needs for the top's movement away from the centre
Tabletop fasteners: the clearance a slotted or figure-8 fastener needs, with a warning if a figure-8 would swing too far

Projects

Save any board to a project, with notes
Several boards per project; rename, duplicate or delete, with undo
Back up every project to a file you choose, and restore it later, through the share sheet

Settings

Metric or imperial units, a default sawing orientation, light or dark theme
A short glossary of flat/quarter/rift-sawn, relative humidity, EMC and fibre saturation point

No ads. No subscription. No account

Pay once. There is no advertising, no in-app purchase and no sign-in. Grainsway never asks for bank or card details.

Works offline, stays on your phone

Grainsway has no internet permission, so it cannot send your projects anywhere. Everything stays on your phone.

Built on published data

Movement coefficients and the EMC method are from the USDA Forest Products Laboratory Wood Handbook, a public-domain reference. Grainsway is a planning aid, not a substitute for a moisture meter or your own test boards on an unfamiliar species.

Screenshots

Grainsway screenshot: Calculate — Calculate

Grainsway screenshot: Humidity — Humidity

Grainsway screenshot: Allowances — Allowances

Grainsway screenshot: Breadboard — Breadboard

Grainsway screenshot: Projects — Projects

Grainsway screenshot: Settings — Settings

Frequently asked questions

How much does Grainsway cost?: Grainsway is a one-time purchase of $1.99 on Google Play. There are no ads, no subscription and no in-app purchases.
Does Grainsway work offline? Do I need an account?: Yes. Grainsway works fully offline, with no account and no sign-in. What you enter stays on your phone.
Does Grainsway collect my personal data?: No. Grainsway never asks for your name, email address or phone number, and it does not send what you enter anywhere. See the privacy policy.

Get Grainsway