Grade × Thickness Calculator

FORMULA

Grade × Thickness Formula

Grade × thickness combines the average grade of a mineralized interval with its true thickness into a single value.

The resulting units depend on the grade and thickness units used. For example, a grade reported in grams per tonne and a thickness measured in meters produces a grade × thickness value in g/t·m.

WORKED EXAMPLE

Grade × Thickness Example

Consider a mineralized interval with an average grade of 2.5 g/t and a true thickness of 10 meters.

A larger grade × thickness value may result from higher grade, greater thickness, or a combination of both. The value therefore provides a compact way to describe the combined grade and thickness of an interval.

GEOLOGICAL USE

How Grade × Thickness Is Used

Grade × thickness can be used as a simple way to compare mineralized intervals by considering both grade and thickness. It can be useful when reviewing drill results, comparing mineralized zones, or summarizing intervals during exploration.

However, grade × thickness is a descriptive metric rather than a complete measure of the geological or economic significance of an intercept. Similar grade × thickness values can represent very different combinations of grade and thickness.

Both intervals have the same grade × thickness value, but their grade and thickness characteristics are substantially different.

INTERVAL GEOMETRY

True Thickness vs. Drillhole Intercept Length

Drillhole intercept length is not necessarily the same as the true thickness of a geological or mineralized zone. The measured interval along a drillhole depends on the angle at which the hole intersects the zone.

When true thickness is known or can reasonably be estimated, using it provides a more geometrically meaningful thickness for a grade × thickness calculation than simply using the drilled interval length.

LIMITATIONS

Important Considerations

Grade × thickness should be interpreted together with the geology of the mineralized interval. The calculation does not account for factors such as mineralized-zone geometry, continuity, density, metallurgical recovery, mining method, dilution, commodity price, or operating costs.

Grade × thickness values should also be compared using consistent units. A value expressed in g/t·m is not numerically equivalent to a value expressed in oz/ton·ft without appropriate unit conversion.

The calculation is therefore best treated as a convenient interval-comparison metric rather than a standalone measure of resource quality or economic value.