ZenLevel vs Model Scale Calculator

ZenLevel turns your iPhone into a precision inclinometer with the calm, deliberate feel of a real machinist's instrument. Built for builders, DIYers, photographers, woodworkers, and anyone who needs something perfectly level, perfectly plumb, or at exactly the right slope. FOUR MEASUREMENT MODES SURFACE — Lay your iPhone flat on a countertop, shelf, or picture frame. The two-axis bubble instrument shows the exact inclination, with digits that roll smoothly between values like a laboratory dial. When you find true level, the interface shifts to a calm, luminous green. PLUMB — Press the back of your iPhone against a vertical surface to check whether it is truly vertical. A tall bubble tube rises and falls with the wall's deviation, and a "check position" warning tells you when the phone is too flat for an accurate reading. CALIBRATE — Every sensor drifts. Place your phone on a surface you trust, wait for the stability meter, and tap ZERO OUT. Offsets persist across launches, and Reset calibration restores factory defaults at any time. HISTORY — Save any measurement to a log grouped by day. Tap an entry to see its details, edit its note, or delete it. HOLD THE READING Measuring under a shelf or behind a cabinet? Tap HOLD to freeze the reading, then take your iPhone out and read it — or save it — at your leisure. Tap RELEASE to go live again. SLOPE UNITS Show every reading in degrees, percent grade, millimetres per metre, or inches per foot. Rise-over-run units make drains, ramps, patios, decks, and gutters easy: a quarter inch per foot is simply 0.25 in/ft. Saved measurements follow your chosen unit and keep the original angle alongside. LANDSCAPE PRECISION MODE Rotate your iPhone to landscape and SURFACE becomes a long horizontal bubble vial for checking frames, shelf edges, and countertops along their length. A tipping indicator helps you keep the phone upright to avoid projection errors. DESIGN THAT FEELS LIKE A REAL TOOL • Deep blacks, subtle glass panels, and a signature zen-green accent • Rolling digit transitions on every live readout • Haptic feedback on level, save, calibration, and tab changes • Rotation-lock detection that guides you when iOS is locked to portrait • Decorative animations pause when Reduce Motion is on PRIVACY FIRST, BY DESIGN • No accounts, no login, no cloud sync • No tracking, no analytics, no advertising • No network requests of any kind • Measurements and calibration stay on your device • No third-party SDKs WHO IT'S FOR • Carpenters and builders checking walls, cabinets, and frames • Plumbers and landscapers setting drain and patio falls • DIY homeowners hanging shelves, pictures, TVs, and mirrors • Photographers aligning tripods and subjects • Woodworkers checking joinery and surfaces ZenLevel isn't a novelty. It's a precision instrument that lives in your pocket, ready to settle "is this level?" in seconds.

A scale converter for people who build models. Pick a scale — HO, N, O, 1:35 armour, 28mm heroic, 1/4" = 1' — type a dimension, and read the answer as you type. Free, offline, no account, no ads. THREE ANSWERS, ONE SCREEN • Real → model — how big is a 40-foot boxcar in HO? • Model → real — this part measures 92 mm; what is that full size? • What scale is this? — give a real length and the model length it has to come out at, and get the ratio. COMPARE ACROSS SCALES A second view takes one measurement and shows it in every scale in a hobby group at once — model railway gauges, military armour, aircraft, tabletop miniatures — with a proportional bar per row so you can judge the sizes by eye instead of reading numbers. UNITS HOBBYISTS ACTUALLY TYPE It parses what you would write on a workbench note: 250mm, 2.5 cm, 5' 6", 5ft 6in, 1 1/2", 3/4", 1-1/2". Feet-and-inches and fractional inches are first-class output formats, not an afterthought — fractions come back as fractions, rounded to the precision you choose. SCALES INCLUDED • Model railways — Z, N, TT, HO, OO, S, O, G and more • Military and armour — 1:16, 1:35, 1:48, 1:72 • Aircraft — 1:32, 1:48, 1:72, 1:144 • Cars — 1:18, 1:24, 1:43, 1:64 • Tabletop and wargaming — 15mm, 28mm heroic, 32mm, 54mm • Architecture — imperial drawing scales like 1/4" = 1' and metric 1:50, 1:100 • Any custom ratio you type WORKS COMPLETELY OFFLINE No account, no sign-in, no sync, no paywall and no advertising. Every calculation happens on your device, and nothing you type is ever sent anywhere. The only thing the app ever sends is anonymous usage data — which scales and modes get used — and you can switch that off in Settings. For model railroaders, scale modellers, miniature painters, RC builders, dollhouse makers, architects and anyone who has ever stood in a hobby shop doing long division on their phone.