Slab — Support

Need help with Slab — the concrete & masonry material estimator? We’re happy to help.

Contact us

Email: jonghyuk.park1105@gmail.com — we usually reply within 1–2 business days.

Quick answers

• Free vs Pro: the Slab and Gravel calculators are free and unlimited. One single in-app purchase (no subscription, ever) unlocks all other materials, dollar cost quotes, saved projects, and PDF/text export.
• Restore a purchase: open Settings → Restore Purchase (also available on the unlock screen). Your unlock is tied to your Apple ID.
• Works offline: Slab needs no account and no internet — it runs fully in airplane mode.
• Units: type feet-inch-fractions like 12' 6 1/2" or switch to metric in Settings.
• Accuracy: bag counts always round up to full bags; material yields follow published Quikrete / Sakrete and CRSI values.

Thanks for using Slab.