Public mineral owner calculators

Calculate Net Mineral Acres and basic Net Royalty Acres

Use two clear educational estimates now. Each calculator shows the formula, explains the inputs, and gives you a number to compare with your records.

Your entries stay in this browser. These calculators do not send, save, or transmit what you enter. Do not enter account, tax, identity, or banking information.

Two calculations you can use now

Start with your deed, probate record, title work, lease, or another document that states the acreage and ownership fraction. An estimate is only as reliable as the records used.

Net Mineral Acres

Net Mineral Acres (NMA) estimate the mineral acres you own after your ownership fraction is applied to the gross tract acres.

Enter two values
The total acres in the tract before your ownership fraction is applied. Look for acreage in the legal description, deed, probate record, or title work.
Your share of the minerals in the tract before lease royalty or unit participation is applied. Enter a simple fraction, percent, or decimal.
Ready Enter your records

Your result will appear here.

Formula: Gross Tract Acres × Mineral Ownership Fraction = NMA

Basic Net Royalty Acres

Net Royalty Acres (NRA) are an older comparison metric, commonly normalized to a 1/8 royalty. NRA are not a replacement for NMA.

Enter two values
Use the NMA stated in reliable title work or the estimate from the calculator on this page.
The royalty fraction reserved in the Oil and Gas Lease. Enter a simple fraction, percent, or decimal.
Ready Enter your records

Your result will appear here.

Formula: NMA × (Lease Royalty ÷ 0.125) = 1/8-Normalized NRA

Worked example

A tract contains 160 gross acres, and the owner holds 1/8 of the minerals. The NMA estimate is 160 × 0.125 = 20 NMA.

If those 20 NMA are subject to a 1/4 lease royalty, the basic NRA estimate is 20 × (0.25 ÷ 0.125) = 40 NRA.

The owner still has an estimated 20 NMA. The 40 NRA figure reflects the royalty compared with a 1/8 baseline and does not mean the owner has more mineral acres.

Member calculator suite

See the full path from acres to an estimated owner decimal

Members can use the advanced workflow for mineral interest decimal, tract Division Order Interest, unit participation, Net Revenue Interest, reverse NMA estimates, allocation interests, estimated royalty payments, and a printable calculation record.

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Advanced result preview

Simplified example only: 20 Net Mineral Acres in a 160-acre tract, a 25% lease royalty, and 160 acres participating in a 640-acre unit. These are estimated calculation stages, not verified Division Order decimals.

Mineral interest decimal0.12500000
Estimated tract royalty decimal0.03125000
Unit participation factor0.25000000
Estimated unit royalty decimal0.00781250

Educational estimate only: This tool does not confirm legal title, verify lease terms, determine whether an operator's Division Order decimal is correct, or guarantee a royalty payment. Compare the result with your lease, recorded documents, operator statement, Division Order, and unit or pooling documents. Actual ownership and payment decimals may depend on title, lease language, unit documents, allocation methods, operator accounting, state law, and your records.