NMA vs NRI: A Landman's Quick Reference

The 30-second answer

NMA and NRI get used interchangeably across the desk every day. They are not the same number, and treating them as if they are is the single most common source of overvaluation in a mineral package. This is the working reference to keep next to your pricing sheet so the math is right the first time.

NMA, net mineral acres, is how much of the mineral estate you own, expressed in acres. It is the product of your ownership fraction and the gross acreage of the tract. It is your ownership.

NRI, net revenue interest, is how much of the production revenue flows to you, expressed as a decimal fraction. It is the product of your acreage share of the unit, the royalty rate, and any burdens. It is your cash flow.

NMA and NRI are related, but they price very differently. One tells you what you hold. The other tells you what it pays. Misread one as the other and you are pricing a different asset than the one in the deed.

NMA: the math

Net mineral acres answers one question: how many acres of the mineral estate do I actually own? The formula is straightforward. NMA equals gross acres multiplied by your ownership fraction.

Clean case: you own an undivided 1/2 interest in the mineral estate of a 320-acre tract. Your NMA is 320 x 0.5 = 160 NMA. No surprises.

Stacked fractions: you own 1/4 of what your grandmother owned, and she owned 1/8 of a 640-acre section. Your ownership fraction is 1/4 x 1/8 = 1/32. NMA = 640 x (1/32) = 20 NMA. Deeds inherited across several generations almost always carry stacked fractions, and the NMA a seller quotes you off memory is usually high. Re-derive it from the recorded conveyance every time.

Severed estates: in Texas the mineral estate is a distinct, severable interest (Texas Property Code Chapter 5 governs conveyances; the mineral estate can be severed from the surface and is the dominant estate). You can own minerals under a tract without owning a square foot of the surface. The NMA math does not change. You multiply your mineral ownership fraction against the tract's gross acreage, regardless of who holds the surface above it.

NRI: the formula that actually prices the deal

Net revenue interest answers a different question: what fraction of the production revenue comes to me after the working interest takes its share? For a leased mineral owner, the formula is NRI = (NMA / unit acres) x royalty rate. When the tract is not pooled, unit acres and gross tract acres are the same number.

Standard Texas lease: you own 40 NMA in a 320-acre tract, leased at a 1/4 royalty. NRI = (40 / 320) x 0.25 = 0.03125, or 3.125%. Every 100 BOE produced from that tract sends 3.125 BOE of royalty revenue your way.

Smaller royalty: same 40 NMA position, but the lease carries a 3/16 (18.75%) royalty instead. NRI = (40 / 320) x 0.1875 = 0.0234, or 2.34%. Identical ownership, roughly 25% less cash flow. The royalty rate swing matters more than most sellers register, which is why the rate on the actual lease document, not the county convention, has to be the number you use.

Burdened by an ORRI: same 40 NMA at 1/4 royalty, but a 2% overriding royalty interest is carved out of the lease. An ORRI burdens the working-interest side, not the mineral side, so your royalty NRI stays 3.125%. If instead you are buying the ORRI rather than the mineral interest, the NRI you are acquiring is simply that 2% override carved off the working interest. Know which side of the waterfall you are buying before you price it.

The payment waterfall: WI, royalty, NPRI, ORRI

Every barrel of revenue from a well gets split before anyone is paid, and each interest type sits in a different spot in the waterfall. Get the order straight and the NRI math stops being confusing.

Off the top, the royalty owner is paid first. That is the lessor's retained royalty, free of drilling and operating cost. An NPRI (non-participating royalty interest) is a royalty-only carveout that also gets paid off the top, but it shares in no lease bonus and no delay rentals. NPRIs are frequently stripped off a mineral estate in an old deed and then traded on their own. An NPRI has no NMA. It has a flat royalty fraction that applies regardless of the underlying lease terms, so if a seller quotes you NMA on an NPRI, the number is meaningless. Ask for the flat royalty fraction and the lease royalty it rides on.

Next, the ORRI (overriding royalty interest) comes out of the working interest, not the mineral estate. It is carved off the lessee's share, typically as compensation to a landman, geologist, or broker who put the deal together, and it expires when the lease expires. That is the structural difference from a mineral or royalty interest, which survives the lease.

Last in line is the working interest (WI). The WI bears 100% of the drilling and operating cost but receives only the leftover revenue after royalty, NPRI, and ORRI burdens are paid. A WI owner's NRI is their working-interest fraction minus all the burdens above them. This is why an 80% WI can have a net revenue interest well under 80% once a 1/4 royalty and an override are subtracted out.

The Texas wrinkles that trip people up

Pooled units. When a tract is pooled into a production unit with surrounding acreage, your NMA ownership in the tract stays constant, but your NRI becomes proportional to your tract's acreage within the unit. A 40-NMA position in a 320-acre tract pooled into a 640-acre unit pays at 320/640 x 40/320 x royalty rate, half the non-pooled rate, but across production from the whole unit. It usually nets out cash-flow-equivalent, yet buyers new to Texas land routinely price pooled interests as if they were standalone.

HBP status. A 40-NMA position on an open, unleased tract trades very differently from the same 40 NMA on a tract held by production (HBP) for another 30 years. The open position carries lease-bonus upside, delay-rental income, and re-lease optionality. The HBP version carries only royalty cash flow at the historical lease rate, often 1/8 or 3/16 on an old lease, with no chance to re-lease at today's 1/4. Same NMA, frequently a 2x to 4x difference in price. The pricing framework lives in our guide on how to value a mineral package in Texas.

Royalty-rate spread in the current market. As of 2026, new leases in the core Permian generally command a 1/4 (25%) royalty, with 1/5 (20%) common just outside the best rock, while many legacy leases are still locked at 1/8 (12.5%) or 3/16 (18.75%). That full spread, 12.5% to 25%, is a 2x NRI swing on identical NMA. When the rock is producing, that translates directly into dollars: active Permian minerals have been trading in a roughly $10,000 to $50,000+ per NMA range depending on production and operator activity, so a misread royalty rate is a five-figure error per acre, not a rounding issue.

Producing vs. non-producing heuristics. Producing minerals tend to trade at roughly 3 to 6 years of trailing monthly royalty income, while leased-but-non-producing minerals follow the 2-to-3-times-most-recent-lease-bonus rule of thumb. Both heuristics depend on the NRI being correct, because cash flow is downstream of NRI, not NMA. Run the wrong interest number and every multiple on top of it is wrong too.

The quick check to run before every offer

Re-derive NMA from the deed. Do not trust the seller's quoted number. Multiply the ownership fraction from the recorded conveyance against the tract's gross acreage from the county plat or runsheet.

Identify the royalty rate from the current lease document, not the county convention. In Texas today rates run from 1/8 on older leases to 1/4 on core post-2015 Permian leases. That spread alone is a 2x NRI swing on identical NMA.

Check for NPRIs, ORRIs, and other burdens. Walk the chain of title back at least 60 years. Any royalty carveout filed at any point in the chain still applies unless it was specifically released. A clean-looking position can hide a 1/16 NPRI from a 1940s deed.

Confirm pooling and HBP status. If the tract sits in a declared unit, apply the tract's acreage share to the NRI math. Then confirm whether a producing well holds the lease. No producing well on the tract or the pooled unit means the lease terminates at the end of its primary term, which changes both the math and the value.

Why your CRM should carry interest type per owner

The errors above all share one root cause: the interest type, the royalty rate, and the burden stack live in someone's head or in scattered runsheet PDFs, not on the owner record. When the math is rebuilt from memory on every call, NMA gets quoted as if it were NRI, an old NPRI gets missed, and a pooled tract gets priced like a standalone one. The dollars lost are real, 2x to 10x overvaluation on stacked-fraction tracts and 20% to 40% NRI swings on a missed NPRI.

The fix is to make interest type a first-class field on every owner record. In Scout, each owner record carries the interest type (MI, RI, NPRI, ORRI, WI), per-tract NMA, working-interest and net-revenue-interest percentages, eNRI, and a $/NMA figure, so the next person to touch the deal sees what the interest actually is, not what the seller called it. Scout holds the interest type you or your title shop recorded; it does not derive it from the chain of title.

Scout is the system of record for the package, the owner database, the four-stage deal pipeline from Under Negotiation through PSA Sent, Signed, and Closed, and the per-deal document vault, not a title or runsheet tool. Title work stays with you and your title shop. What Scout holds is the deal and the documents, with the interest details, NMA, WI/NRI, and eNRI, sitting on the owner record instead of being rebuilt from memory on every call. The pricing call stays yours: the right interest numbers are on the record, but what the position is worth is still your analysis to run. See the owner database in Scout, or run the numbers against a live permit feed first with the free TRRC Permit Tracker.