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Oil and Gas Royalty Calculator

This oil and gas royalty calculator works out a decimal interest from net mineral acres, unit acres and the lease royalty, then what one month of production pays, to the cent. Every step shows its formula, and nothing you type leaves your browser.

  • Version 2.0.0, updated October 6, 2026
  • Arithmetic only: no assumed prices, production or tax
  • Nothing you type is sent or stored

The formula. Decimal interest = net mineral acres ÷ unit acres × lease royalty. One month of gross royalty = decimal × volume × price, line by line for oil, gas and natural gas liquids. Deductions and tax are optional and shown separately.

A worked example

This is a synthetic example for checking the arithmetic. It is not a market price, a real well or anyone’s check.

  1. Decimal. 40 net mineral acres in a 640 acre unit under a 3/16 lease: 40 ÷ 640 × 0.1875 = 0.01171875.
  2. One month. 0.01171875 × 10,000 barrels × $75 per barrel = $8,789.0625, shown as $8,789.06.
  3. Twelve identical months. $8,789.0625 × 12 = $105,468.75. This repeats the month entered. It is not a forecast: real wells decline, and prices move.
Oil and Gas Royalty Calculator worked example: 40 net mineral acres in a 640 acre unit at a 3/16 royalty give a decimal of 0.01171875 and $8,789.06 for one month
The worked example in three steps. The decimal is exact; rounding to the cent happens once, at the end.

Press Load the worked example above to see the same numbers in the tool.

What each input means

Gross acres and your share
If you own 1/4 of the minerals under a 160 acre tract, you hold 160 × 1/4 = 40 net mineral acres. The helper applies your share once; the decimal never applies it again.
Net mineral acres in the unit
The net mineral acres of yours that sit inside the drilling or spacing unit. They cannot exceed the unit acres, and the calculator rejects that entry.
Unit acres
The size of the whole unit the well produces from, often 640 or 1,280 acres. If the well produces only from your tract, the tract acres are the unit acres.
Lease royalty
The share of production your lease reserves, such as 1/8, 3/16 or 1/4. Type a fraction, a percent with a % sign, or a decimal below 1. A bare number such as 20 is rejected because it could mean 20% or a typing error.
Decimal interest
Your share of the revenue from the unit, as a division order states it. A royalty decimal is not the same as a working interest owner’s net revenue interest, which also bears costs.
Volumes and prices
Oil in barrels at a price per barrel. Gas in Mcf or MMBtu, priced per Mcf or per MMBtu; if the units differ, enter the heating value from your statement. The tool does not assume one. Natural gas liquids in gallons at a price per gallon.

Deductions and tax

Both are optional and both are taken from gross: net = gross − deductions − tax. Deductions can be a percent of gross or a fixed dollar amount per month; tax is a percent of gross. This is a simple, visible model. Real statements may compute severance tax on a different base, may charge costs line by line, and some leases allow no post production deductions at all. If deductions and tax add up to more than gross, the calculator stops and says so rather than showing zero.

For state tax treatment, see the state royalty tax reference, which says which figures are checked and which are not.

Scenarios are separate and optional

The main result is always the arithmetic on what you entered. Two optional scenarios sit beside it and never change it:

Price change. Gross × (1 + your percent change), for a low and a high case you choose.

Monthly decline. Month 1 equals the gross above, and each later month is lower by the percent you choose: total = gross × Σ(1 − d)m−1 for m = 1 to N. A simple curve you define, not a decline forecast for any well.

The change record lists how this calculator has changed between versions.

Checking a statement

The Check a statement tab recomputes owner value as decimal × volume × price from figures you copy off a check stub, then shows the difference and the decimal the statement implies. Differences have ordinary causes: realized prices that differ from posted prices, prior period adjustments, unit allocation and lease terms. The tool points to the arithmetic; it cannot say whether money is owed.

Common questions about royalty payments

How do you calculate an oil and gas royalty payment?

Multiply the volume sold by the price and by your decimal interest, then subtract any deductions your lease allows and the state’s severance tax. For oil that is barrels times the price per barrel times your decimal; for gas, the volume times the price in the same unit, Mcf or MMBtu, times your decimal. The calculator does this for oil, gas and natural gas liquids together and shows every step.

What is a royalty decimal, or decimal interest?

It is the share of a well’s or a unit’s production revenue that belongs to you, written as a decimal. In a pooled unit it is your net mineral acres divided by the unit’s acres, times your lease royalty rate: 10 acres in a 640 acre unit at a 3/16 royalty gives 0.0029296875. Division orders and check stubs often print it to eight decimal places.

Does the calculator show my check before or after taxes?

Both. It shows the gross royalty first, then subtracts the deductions and the severance tax rate you enter, so each step is visible. It does not estimate income tax, which depends on your own return; the tax page explains how each state treats royalty income.

What if my tract is not pooled into a unit?

If a well produces from a single lease that is not pooled, your decimal is your net mineral acres divided by the acres in that lease, times your royalty rate. Enter the lease acreage where the calculator asks for unit acres.

Why does my check not match the calculator?

The usual reasons are a realized price different from the one entered, deductions that were not entered, a decimal on the division order that differs from yours, a price from a different month than the production, or an adjustment for an earlier month. Compare each line of the statement with the calculator’s steps.

Privacy

The calculator runs in this browser tab. The page loads its own files from this website and makes no other requests: no analytics, no advertising and no form submission. The optional share link keeps your numbers after the # in the address, which browsers do not send to any server; it never includes a name or a document. Printing uses your browser’s own print dialog.

Embed the calculator

Publishers may embed the calculator. It carries no offers, sign-ups or tracking. A visible credit link is welcome but optional, and you choose whether it is followed.

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Cite this calculator

American Mineral Registry. "Oil and gas royalty calculator." Version 2.0.0, October 6, 2026. https://americanmineralregistry.com/research/oil-and-gas-royalty-calculator

Version history

2.0.0, October 6, 2026. Exact fraction arithmetic shown to the cent; strict input checks that block results on any invalid entry; separate oil, gas and NGL lines with explicit gas units; optional deductions and tax with no silent clamping; optional, visible scenarios; statement check; copy, print and share. Replaced 1.x.

1.x, June to August 2026. Decimal and a rounded monthly figure with a default annual range built from hidden assumptions. Retired; see the change record.

General information, not legal, tax or financial advice. The calculator does arithmetic on the numbers you enter; your division order, lease and statements control. Published by American Mineral Registry, which also runs a commercial service for owners; see how the two relate.