Ore Waste Ratio Calculator

The ore:waste ratio (a stripping-style production ratio) is waste divided by ore, reported as X : 1.

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Enter Values

Ore mined (t or BCM)

Waste removed (t or BCM)

Period worked (hours, optional)

Enter your values and press Calculate to see results.

Before you rely on this: First-pass guide only. Verify safety-critical or regulated work against the relevant standards, your project requirements and a qualified professional.

How to use this calculator

Enter ore mined and waste removed for the same period, both in the SAME unit — either tonnes or bank cubic metres (BCM) — do not mix.
Optionally enter the hours worked in that period to also get the average mining rate (per hour).
Read the ore:waste ratio, the total material moved and the ore/waste percentage split; use the same-unit rule so the ratio is meaningful.

How it works

The ore:waste ratio (a stripping-style production ratio) is waste divided by ore, reported as X : 1. Total material moved is simply ore plus waste, and the ore/waste percentage split expresses each as a share of that total. When you supply the period worked, the average mining rate is total material divided by hours (in the same unit per hour).

Both quantities must be in the same unit for the ratio to make sense: tonnes with tonnes, or BCM with BCM. Because tonnes depend on density and BCM depend on swell, converting between them changes the numbers — use the BCM/LCM/Tonnes converter first if your ore and waste were measured in different units. This tool assumes both inputs are already consistent.

Worked example

Monthly open-pit reconciliation. A pit moves 250,000 t of ore and 1,500,000 t of waste over a 720-hour month. Total material = 250,000 + 1,500,000 = 1,750,000 t. Ore : waste ratio = 1,500,000 ÷ 250,000 = 6 : 1. Ore is 14.3 % of total material and waste is 85.7 %. Mining rate = 1,750,000 ÷ 720 = 2,430.6 t/hour.

Common mistakes

Mixing units — entering ore in tonnes and waste in BCM. Density and swell differ, so the ratio is wrong unless both are the same unit.
Swapping ore and waste. Ratio is waste ÷ ore; putting ore on top gives the reciprocal and a misleadingly low figure.
Reading the ratio as a cost or a mine plan. It is a material-movement ratio only — the true economic stripping ratio depends on cut-off grade, dilution, prices and costs, so treat this as a reconciliation estimate to verify against site data.

Frequently asked questions

Is this the same as strip ratio?

It uses the same waste ÷ ore formula, but this tool is a production/reconciliation view: alongside the ratio it gives total material moved, the ore/waste percentage split and an optional mining rate. Use the dedicated Strip Ratio Calculator if you only want the single ratio number.

Can I use tonnes or bank cubic metres?

Either — but both inputs must be the SAME unit. Tonnes with tonnes, or BCM with BCM. Mixing them is invalid because tonnage depends on density and BCM depends on swell factor.

What does a 6:1 ratio mean?

Six units of waste are moved for every one unit of ore. Higher ratios mean more waste stripping per unit of ore, which usually raises the cost per unit of ore recovered.

Does the ratio include the ore in the total?

No. The ratio is waste ÷ ore only. The separate 'total material moved' output does include both ore and waste, which is what the mining rate is based on.

Tip: Enter any known values to calculate the remaining results.

All calculations run in your browser. Your inputs are never saved or transmitted.