Calculators

Metal Detecting Calculators

Metal detecting is mostly a reference hobby rather than a mathematical one, so there are nine tools here rather than thirty. Every one of them answers a question whose answer genuinely depends on your own ground, your own machine or your own find, which is exactly the kind of question that is worth opening a page for. Each runs in the browser, keeps nothing, and shows gear matched to the answer it produced.

Covering ground

• Coil Coverage and Sweep Time Calculator Work out how long a site takes to cover properly from your coil width, sweep speed and overlap, in hours per acre.
• Search Grid Planner Turn a site's dimensions into a number of lanes, a lane spacing and a total walking distance, so a field gets covered once properly instead of three times badly.
• Dig Time Budget Calculator How many targets you can actually recover in the time you have, from signal density, trash ratio and recovery time per hole.

Depth and coils

• Expected Detection Depth Calculator Estimate realistic depth for a target from its size, your coil diameter and how mineralised your soil is.
• Coil Size Selector Which coil diameter suits the site in front of you, from trash density, target size and how much ground you need to cover.

The machine

• Detector Battery Runtime Calculator How many hunts you get from a charge or a set of cells, and what wireless audio and backlight actually cost you in runtime.

What a find is worth

• Gold Nugget Weight to Value Calculator Convert a nugget's weight in grams, grains or pennyweight to a melt value at your own purity assumption and spot price.
• Silver Coin Melt Value Calculator Melt value for common silver coins from their published fineness and weight, at whatever spot price you enter.
• Coin Find Value Calculator Total the face value, weight and rough silver content of a season of coin finds, so you can see what a site is actually returning.

Researched, not professional advice. These tools produce estimates from the figures you enter and from published manufacturer specifications. Depth, coverage and runtime all vary with soil, moisture, temperature and how the machine is set up. Metal values are melt estimates only and are not an offer, a valuation or a guarantee of what any buyer will pay. As an Amazon Associate we earn from qualifying purchases.