Tire Geometry Delta

Tire size calculator: compare nominal tire dimensions from the size notation you enter. Tire Geometry Delta is a tire size calculator for the dimensions you enter: width, aspect ratio and rim diameter.

COMPARE TWO SIZES IN FREE
• Enter notation such as 205/55R16, or use separate fields.
• Read nominal diameter, circumference, sidewall, radius and rim dimensions.
• See signed differences and percentages beside labelled baseline and proposed sizes.
• Switch between metric and inch display, and km/h or mph.
• Review a nominal speed-ratio estimate at an indicated 60.
• Read the formulas and calculation limits in Settings.

OPTIONAL LIFETIME PRO
A one-time Google Play purchase adds:
• Up to four total setups: one baseline and three alternatives.
• A custom indicated speed and a proportional nominal diameter scale aid.
• Saved named comparisons with notes, search, sorting and duplication.
• Reusable size presets kept independently of comparison history.
• JSON backup and validated import with a merge preview.
• CSV and text export through Android’s document picker.

Lifetime Pro is not a subscription. Google Play shows the price in your local currency. Restore purchases uses the Google Play account that owns the upgrade; notebook backups do not contain purchase ownership.

LOCAL RECORDS, CLEAR CHOICES
Core calculations work offline. There is no PatchMedia account, advertising, first-party analytics or cloud sync. Your comparisons, presets and notes remain on your device during normal use. Google Play processes billing and technical Billing SDK diagnostics. Files go only to the destination you choose; a cloud-backed document provider may sync them under its own policy. Automatic Android backup and device transfer are disabled, so export a Pro JSON backup before clearing storage or uninstalling.

NOMINAL GEOMETRY ONLY
Results are calculated from your inputs. Actual tire dimensions vary by manufacturer and wheel width. The app does not determine fitment, clearance, offset, load, pressure, handling, roadworthiness or legal compliance. Speed results are nominal size-ratio estimates, not measured vehicle speed or speedometer calibration. Verify any installation or vehicle decision with appropriate manufacturer information and qualified guidance.

Support: contact@patch-media.com
Privacy: https://patch-media.com/privacy/tire-geometry-delta/

For drivers considering Tire and wheel size, this tire comparison worksheet can help organize nominal size differences before a conversation with an installer. Bring the entered dimensions and their percentage changes as discussion notes, while leaving clearance, load suitability and installation decisions to appropriate checks.

Recent changes:
Initial release of Tire Geometry Delta.
Compare two nominal tire sizes, read labelled geometry and speed-ratio estimates, and choose metric or inch display.
Optional one-time Lifetime Pro adds four setups, custom speed, a saved comparison notebook, reusable presets and JSON/CSV/text file tools.