Net Mineral Acres vs Net Royalty Acres | Offer Units

Net mineral acres vs net royalty acres matters the moment two offers use different units, because a net royalty acre has no single meaning. NARO describes it as a royalty normalized against a 1/8 standard, so 40 net mineral acres leased at 1/4 count as 80 net royalty acres (NARO, Oct 2026), while LandBridge's annual report defines it on a 100% royalty basis instead (LandBridge, Form 10-K, Dec 2025). The same $100,000 offer is about $667 per net royalty acre on one basis and $5,333 on the other (Flat River Minerals, Oct 2026).

This page explains what each offer unit measures, shows how royalty companies define a net royalty acre in their SEC filings, works through how a royalty decimal is estimated, and gives a converter that refuses to convert until it knows which convention an offer uses. Every definition comes from NARO, a state statute, a company filing or the buyer that published it.

Key Takeaways

NARO normalises net royalty acres to a 1/8 royalty (NARO, Oct 2026).
LandBridge defines a net royalty acre on a 100% royalty basis (LandBridge, Form 10-K, Dec 2025).
The same $100,000 offer is $666 or $5,333 per net royalty acre, by convention (Flat River Minerals, Oct 2026).
Dorchester Minerals multiplies by eight to normalise to a 1/8 royalty (Dorchester Minerals, Form 10-K, Dec 2025).
Alliance Resource Partners counts 100 acres at 25% as 200 net royalty acres (Alliance Resource Partners, Form 10-K, Dec 2025).
Viper Energy defines net royalty acres as acres times royalty, with no 1/8 divisor (Viper Energy, Form 10-K, Dec 2025).
Sitio said the industry typically standardized net royalty acres to 12.5% (Sitio Royalties, Form 10-K, Dec 2023).
A larger net royalty acre figure does not mean more mineral acres (NARO, Oct 2026).
20 net mineral acres in a 640 acre unit at 1/4 give a 0.0078125 decimal (NARO, Oct 2026).
Oklahoma requires revenue decimals to at least six decimal places (Oklahoma Statutes, 52 O.S. 570.12, Oct 2026).
Texas lets a payor require a division order stating the decimal interest (Tex. Nat. Res. Code 91.402, Oct 2026).
NARO calls 36 to 60 times monthly income a triage rule, not an appraisal (NARO, Oct 2026).

What is the difference between net mineral acres and net royalty acres?

Net mineral acres measure how much of the minerals you own; net royalty acres measure your royalty, scaled to a convention. One interest can therefore carry three different numbers.

Net mineral acres vs net royalty acres: 20 net mineral acres at a 1/4 royalty equal 40 net royalty acres on a 1/8 basis and 5 on a 100% basis — Figure 1: The same 20 net mineral acres at a 1/4 royalty are 40 net royalty acres on a 1/8 basis and 5 on a 100% basis. Source: NARO, Calculate Net Mineral Acres and basic Net Royalty Acres, Oct 2026. Drawn by American Mineral Registry from the cited source, checked October 8, 2026.

What is a net mineral acre?

Your fraction of the minerals times the acres in the tract.

NARO defines net mineral acres as the gross tract acres multiplied by the owner's fraction of the minerals in that tract (NARO, Oct 2026).
NARO's example: owning half the minerals under a 100 acre tract is 50 net mineral acres (NARO, Oct 2026).
LandBridge counts gross mineral acres as every acre in which it owns any mineral or royalty interest, whatever the size of that interest (LandBridge, Form 10-K, Dec 2025).

What is a net royalty acre?

A royalty share expressed in acres, and the scale depends on who is counting.

NARO says net royalty acres normalise royalty rates against a 1/8 standard, so 40 net mineral acres at 1/4 are 80 net royalty acres while 40 at 1/8 are 40 (NARO, Oct 2026).
NARO calls net royalty acres an older comparison metric that does not replace net mineral acres (NARO, Oct 2026).
NARO warns that 20 net mineral acres at a 1/4 royalty are 40 net royalty acres on a 1/8 baseline but still only 20 net mineral acres (NARO, Oct 2026).
NARO says many professionals value minerals per net royalty acre because the unit evens out differences in royalty rate (NARO, Oct 2026).

Why can one offer differ eightfold per net royalty acre?

Because the 1/8 basis scales a modern royalty up and the 100% basis does not. Flat River Minerals, a buyer, shows the same $100,000 offer at $666 and at $5,333 per net royalty acre.

The same $100,000 offer for 100 net mineral acres at an 18.75% royalty: about $667 per net royalty acre on a 1/8 basis and $5,333 on a 100% basis — Figure 2: The price per net royalty acre is eight times higher on the 100% basis, though the offer and the interest are identical. Source: Flat River Minerals, Frequently Asked Questions, Oct 2026. Drawn by American Mineral Registry from the cited source, checked October 8, 2026.

How does the 1/8 basis work?

It divides your royalty by 1/8, so any royalty above 1/8 produces more net royalty acres than net mineral acres.

NARO gives the 1/8 formula as net royalty acres equal net mineral acres times the lease royalty divided by 1/8 (NARO, Oct 2026).
Flat River Minerals says 100 net mineral acres leased at 18.75% are 150 net royalty acres on a 1/8 basis, so a $100,000 offer is $666 per net royalty acre (Flat River Minerals, Oct 2026).
Flat River Minerals says the industry uses two definitions, which it calls the old way and the modern way (Flat River Minerals, Oct 2026).

How does the 100% basis work?

It multiplies acres by the royalty and stops there.

Flat River Minerals says the same 100 net mineral acres at 18.75% are 18.75 net royalty acres on a 100% basis, so the same offer is $5,333 per net royalty acre (Flat River Minerals, Oct 2026).
LandBridge's filing says a 1/4 royalty in 100 gross mineral acres is 25 net royalty acres on its 100% basis (LandBridge, Form 10-K, Dec 2025).

Putting two whole offers on equal terms is covered in compare mineral rights offers.

How do royalty companies define a net royalty acre?

Mostly on a 1/8 basis, but not all. Of six public royalty companies whose annual reports were read, four normalise to 1/8, one states a 100% basis, and one multiplies acres by royalty with no 1/8 divisor.

Net royalty acre conventions in SEC filings: 4 companies normalise to 1/8, 1 states a 100% basis, 1 multiplies acres by royalty with no divisor — Figure 3: Most filings read use the 1/8 basis, but two of six do not, so a per acre number cannot be compared without the convention. Source: U.S. Securities and Exchange Commission, EDGAR filings, Dec 2025. Drawn by American Mineral Registry from the cited source, checked October 8, 2026.

Which companies use the 1/8 basis?

Four of the six, in their own glossaries.

Dorchester Minerals defines a net royalty acre as net acres times the lease royalty times eight, to normalise to a 1/8 royalty (Dorchester Minerals, Form 10-K, Dec 2025).
Alliance Resource Partners says 100 net mineral acres leased at 25% equal 200 net royalty acres normalized to 1/8 (Alliance Resource Partners, Form 10-K, Dec 2025).
Texas Pacific Land labels its additional royalty acreage as net royalty acres normalized to 1/8 (Texas Pacific Land, Form 10-K, Dec 2025).
Sitio Royalties stated that the industry typically standardises net royalty acres to a 12.5% royalty (Sitio Royalties, Form 10-K, Dec 2023).

Which companies use something else?

LandBridge states a 100% basis outright; Viper's formula amounts to the same thing.

LandBridge defines a net royalty acre as mineral ownership standardized to a 100% royalty (LandBridge, Form 10-K, Dec 2025).
Viper Energy defines net royalty acres as net mineral acres multiplied by the average lease royalty and other burdens, with no 1/8 divisor (Viper Energy, Form 10-K, Dec 2025).
Sitio also reported its position in 100% royalty acres by multiplying its 1/8 basis figure by 12.5%, turning 252,297 net royalty acres into 31,538 (Sitio Royalties, Form 10-K, Dec 2023).
Sitio counted unleased minerals at an assumed royalty, 25% in the Permian and 20% in the Eagle Ford, Bakken and DJ basins, so a figure for unleased acreage rests on an assumption (Sitio Royalties, Form 10-K, Dec 2023).

How is a royalty decimal worked out?

Your net mineral acres divided by the acres in the unit, times your lease royalty. The result is an estimate; the payor's decimal comes from a title opinion.

NARO's worked example of a royalty decimal: 20 net mineral acres divided by 640 unit acres, times a 1/4 royalty, gives 0.0078125 — Figure 4: NARO's worked example turns 20 net mineral acres in a 640 acre unit at a 1/4 royalty into a decimal of 0.0078125. Source: NARO, How to Estimate Your Royalty Decimal, Oct 2026. Drawn by American Mineral Registry from the cited source, checked October 8, 2026.

What is the formula?

NARO gives one formula and a list of conditions on it.

NARO's estimate for a leased owner is net mineral acres in the unit, divided by the acres used to allocate production, times the lease royalty (NARO, Oct 2026).
NARO's example: 20 net mineral acres in a 640 acre unit under a 1/4 royalty give a decimal of 0.0078125 (NARO, Oct 2026).
NARO says the formula is an estimate, not a title or payment rule (NARO, Oct 2026).
NARO says interests across several tracts, leases, depths or dates are worked out piece by piece and added only for the same well and payment period (NARO, Oct 2026).

Where does the payor's decimal come from?

From a title opinion, and state law sets how it is shown.

The Texas A&M Real Estate Center says the decimal on a division order comes from a title opinion by the purchaser's or lessee's attorney (Texas A&M Real Estate Center, Nov 2009).
Texas lets a payor require a division order stating the payee's fractional or decimal interest and the type of interest (Tex. Nat. Res. Code 91.402, Oct 2026).
Oklahoma requires every royalty payment to show the owner's interest as a decimal, calculated to at least the sixth decimal place (Oklahoma Statutes, 52 O.S. 570.12, Oct 2026).
NARO says the payment decimal may be labeled NRI, DOI, owner decimal or payment decimal, so the label alone does not identify the interest (NARO, Oct 2026).

What a check should pay from a decimal and production is worked out in the oil and gas royalty calculator.

How do I compare offers priced in different units?

Convert both to the same unit, and only once you know each offer's convention. A per acre price, a multiple of monthly income and a total price each leave out something the others include.

What each offer unit measures and what to ask: per net mineral acre, per net royalty acre, multiple of monthly income, and total dollars — Figure 5: Each unit answers a different question, and each needs one fact from the buyer before it can be compared. Source: NARO, Net Mineral Acres vs. Net Royalty Acres, Oct 2026. Drawn by American Mineral Registry from the cited source, checked October 8, 2026.

Offer unit converter

Converts only when it knows what it needs: your net mineral acres, your lease royalty, and which net royalty acre convention the offer uses. If the offer does not say, ask the buyer in writing before converting. Nothing is sent or stored.

Your net mineral acres

Lease royalty, as a fraction or percent (for example 3/16 or 18.75%)

Net royalty acre convention the offer uses

Offer total, in dollars (optional)

Enter your net mineral acres and lease royalty.

How do I convert between net mineral and net royalty acres?

Multiply by the royalty, then divide by 1/8 only if the offer uses the 1/8 basis.

On the 1/8 basis, net royalty acres equal net mineral acres times the royalty divided by 1/8 (NARO, Oct 2026).
On the 100% basis, net royalty acres equal net mineral acres times the royalty (Flat River Minerals, Oct 2026).
Diamondback's 2022 filing defined Viper's net royalty acres from gross acreage times the average royalty, a different wording from its 2025 definition, so even one company's convention can change (Diamondback Energy, Form 10-K, Dec 2022).

What about offers priced as months of income?

They measure checks, not acres, and NARO treats them as a first screen only.

NARO lists 36 to 60 times recent average monthly royalty income as an informal rule of thumb for producing minerals (NARO, Oct 2026).
NARO lists three times the lease bonus as an informal per acre rule of thumb for nonproducing minerals (NARO, Oct 2026).
NARO says these rules of thumb are for triage, are not appraisals and can be very wrong (NARO, Oct 2026).

Holding an offer against your own projection of the checks is the job of sell or keep mineral royalties.

Methodology and Sources

Definitions come from NARO's owner guides and calculators, the Texas and Oklahoma statutes on division orders and payment statements, and the glossaries of six public mineral and royalty companies' annual reports on SEC EDGAR, all read on October 8, 2026. Company definitions are reported as each filing words them and dated by the fiscal year the filing covers; where a filing gives a formula without naming its basis, the page says so. Flat River Minerals' example is a buyer's own illustration. The converter applies the two definitions quoted here and nothing else, and it does not value an interest. The page is rechecked when the sources change.

Glossary

Gross acre: every acre in a tract, before any ownership fraction is applied.
Net mineral acre: gross acres times your fraction of the minerals.
Net royalty acre: a royalty share expressed in acres, on a 1/8 or a 100% basis depending on who counts.
1/8 basis: a convention that scales every royalty against a one eighth royalty.
100% basis: a convention that multiplies acres by the royalty with no scaling.
Royalty decimal: your share of a well's production, shown on the division order and check stub.
Division order: the payor's form, signed by the owner, confirming the decimal it pays.
Unit: the acres pooled together around a well, over which production is shared.
NRI: net revenue interest, one label for a payment decimal.

Net Mineral Acres vs Net Royalty Acres: Comparing Offer Units