A Surette Data Systems app
Precious Metal PWA Calculator
MetalsCalc turns live Au/Ag/Pt spot prices and your custom buy percentages into an instant offer — and a finished invoice — on any phone. No spreadsheets, no signal required.
More app details below
App Screenshots
The Problem
A scale and a pocket calculator aren't enough when you're buying gold rings, silver coins, and platinum scrap in the same transaction — with a customer waiting. One wrong purity grade or a stale spot price can cost you the deal or eat your margin.
Gold, silver, and platinum spot prices auto-fetched from gold-api.com and cached locally — falls back to manual override when offline.
List mode for multi-item buys grouped by category, Single for one item, Batch for identical quantities — pick the right tool for the transaction.
Known coins and bullion products have preset weights so you only need to confirm quantity — no manual gram entry for common items.
Build a finished customer invoice from your buy list, add customer details, and export as PDF, shareable photo, or email in one step.
Built for the Field
Key Features Delivered
Auto-fetched Au/Ag/Pt rates from gold-api.com, cached offline, with manual entry fallback.
Set your buy percentage per metal type and adjust purity defaults to match your buying standards.
Add multiple items grouped by metal category and get a running total offer for the entire transaction.
Calculate one item at a time with full grade, weight, and purity detail.
Process multiple identical items at once — perfect for lots of the same coin or bar.
Pre-loaded weight references for popular coins and bullion products reduce manual entry errors.
Displays target sell price alongside your offer so you can track margin on every item.
Finished customer invoices as PDF, shareable photo, or email — with your business name and contact info.
Calculations run entirely on-device. No signal, no problem — MetalsCalc works anywhere you buy.
Any Language
MetalsCalc can be localized for field labels, purity references, invoice headings, and currency display. English, Spanish, or another language can be built into a custom version tailored to your market.
Try It Free
MetalsCalc runs in any modern browser. Add it to your home screen as a PWA for the full offline experience. A custom version with your logo, buy percentages, and purity presets locked in is available through the custom app program.
Custom Version
A custom build can lock in your business name, logo, default buy percentages, purity tables, and invoice template — so every counter person uses the same settings without adjusting anything.
