Ruler and grid
Use centimeter, millimeter, and inch references with a fullscreen measurement grid.
iPhone and iPad measurement tools
Ruler Studio
A clean ruler, grid, and ring sizing workspace for quick physical measurements. Calibrate with a standard card, switch units, and keep the tools ready when you need a precise reference.
Core tools
Built for fast, practical measurement.
Ruler Studio keeps measurement tools simple and local. No account is required, and app settings stay on your device.
Ring sizer
Align a physical ring with the on-screen guide to estimate US, UK, EU, and JP sizes.
Calibration
Fine tune screen measurements using a standard card so the ruler matches your device.
In-app purchase
One-time unlock only.
Ruler Studio uses a single non-consumable purchase: Ruler Pro Lifetime. Product ID: com.sb.ruler.pro.lifetime. No subscriptions are planned for this app.
Support
Need help with Ruler Studio?
For App Store review or customer support, contact SB Apps at spyrosbousios@gmail.com.
Calibration help
Use the calibration tool with a standard card and measure from the same viewing angle for best results.
Purchase help
Ruler Pro Lifetime is restored through the App Store account that originally purchased it.