A resource estimate quantifies the amount of mineralisation in the ground. It combines the grade of the ore with its physical dimensions to calculate how much metal could potentially be extracted. Formal resource estimates are prepared under the JORC Code by a Competent Person. This calculator gives investors a rapid back-of-envelope figure to assess the scale of a discovery before official numbers are released.
| RESOURCE ESTIMATORTonnes | |
|---|---|
| COMMODITY | |
| GRADE% | |
| LENGTH/STRIKE | |
| DEPTH | |
| THICKNESS/WIDTH | |
| SPECIFIC GRAVITYsg | |
| TONNES | 0 |
| CONTAINED METALt | 0 |
| AuEqoz | 0 |
| POTENTIAL | - |
| RESOURCE ESTIMATOROunces | |
|---|---|
| COMMODITY | |
| GRADEg/t | |
| LENGTH/STRIKE | |
| DEPTH | |
| THICKNESS/WIDTH | |
| SPECIFIC GRAVITYsg | |
| TONNES | 0 |
| CONTAINED METALoz | 0 |
| AuEqoz | 0 |
| POTENTIAL | - |
| RESOURCE SIZE CLASSIFICATIONS |
|
|||||||
|---|---|---|---|---|---|---|---|---|
|
|
Gold Moz |
Silver Moz |
Platinum Moz |
Palladium Moz |
Copper Mt |
Nickel Mt |
Zinc-Pb Mt |
Lithium Mt |
| Tier 1 (Giant) | 6 | 300 | 10 | 10 | 5 | 1 | 12 | 1 |
| Tier 2 (Major) | 1 | 50 | 2 | 2 | 1 | 0.1 | 3 | 0.2 |
| Tier 3 (Moderate) | 0.1 | 5 | 0.2 | 0.2 | 0.1 | 0.01 | 0.3 | 0.02 |
Mining deposits are ranked from Tier 1 to Tier 4 based on resource size, grade, mine life, and cost position. Tier 1 is world-class. Tier 4 is small and marginal. Once the Resource Calculator returns your contained metal figure, benchmark it against the thresholds below to quickly assess where this discovery sits.
| Tier | Gold | Copper | Nickel | Lithium (Li2O) |
|---|---|---|---|---|
| Tier 1 (World-class) | > 5 Moz | > 5 Mt Cu | > 500 Kt Ni | > 2 Mt Li2O |
| Tier 2 (Significant) | 2 – 5 Moz | 1 – 5 Mt Cu | 100 – 500 Kt Ni | 500 Kt – 2 Mt Li2O |
| Tier 3 (Moderate) | 500 Koz – 2 Moz | 250 Kt – 1 Mt Cu | 25 – 100 Kt Ni | 100 – 500 Kt Li2O |
| Tier 4 (Small / Marginal) | < 500 Koz | < 250 Kt Cu | < 25 Kt Ni | < 100 Kt Li2O |
Not sure whether the grade is strong enough to support a Tier 1 classification? Check our commodities grade guide for low, medium, and high grade thresholds across every major commodity.
Select your commodity
Choose from the dropdown to set the correct unit parameters.
Enter the dimensions
Input the strike length, depth, and thickness or width of the mineralised zone in metres.
Add the grade
Enter the grade for your commodity (% for base metals, g/t for precious metals).
Read the output
The calculator returns total tonnage and contained metal. Use the Tonnes estimator for base metals; use the Ounces estimator for precious metals.
Benchmark
Compare your contained metal figure against the Tier 1 to Tier 4 thresholds above.
Base metals (copper, nickel, lithium) are reported in percentage grade and contained metal in tonnes. Precious metals (gold, silver, platinum group metals) are reported in grams per tonne and contained metal in ounces. Both estimators are available in this tool.
Before assay results are back, use the Visual Logs Estimator to convert visual core observations into an estimated grade — then run that figure through the Resource Calculator to get an early tonnage indication.
A Tier 1 deposit is a world-class mineral discovery characterised by large resource size, high grade, long mine life (typically 10+ years), low operating costs, and significant annual production. Tier 1 assets are rare and attract major mining company interest. Examples include Olympic Dam (copper/uranium) and Boddington (gold).
A Tier 2 deposit is significant but not world-class. It has solid economics, a reasonable resource size, and is viable over a long mine life — but sits below the scale and cost profile of a Tier 1 asset. Many successful ASX-listed producers operate Tier 2 deposits.
As a general guide, a gold resource above 5 million ounces (Moz) is considered Tier 1 scale. Mine life, production rate, and all-in sustaining cost (AISC) also factor into the classification — a high-cost, short-life 5 Moz deposit is not a true Tier 1.
Tonnage = Strike Length x Depth x Thickness x Specific Gravity. Contained metal is then calculated by applying the grade to the tonnage figure. The calculator handles this automatically.
No. This calculator provides a rough estimate for orientation only. A formal JORC resource requires detailed geological data, systematic sampling, and independent certification by a Competent Person.
The calculator supports the major ASX-listed commodities including gold, silver, copper, nickel, and lithium. Select your commodity from the dropdown to begin.
