Use this free calculator to estimate your oil and gas royalty payment, check the decimal interest on your division order, and work out your net mineral acres. It is built for Pennsylvania landowners in the Marcellus and Utica shale, but the math works for any lease.
Enter what you know. The numbers update as you type. Example values are filled in to start.
Estimates only. Actual payments depend on your lease language, the unit allocation, the sale price the operator receives, deductions, and production that changes from month to month. This is not legal advice.
How oil and gas royalties are calculated
Your royalty is your share of the money from oil and gas sold from the well or unit. The basic formula is:
Royalty = unit production × price × your decimal interest − any allowed deductions
Your decimal interest is the key number. It is the fraction of total unit production that is paid to you, and it appears on your division order and check stubs.
Step 1: Net mineral acres
Net mineral acres measure how much of the minerals you actually own. Multiply the gross acres in your tract by your fractional ownership of the minerals.
Example: you and your three siblings inherited your parents’ 80-acre farm in equal shares, but a past owner kept half of the oil and gas rights. Your share is 1/4 of 1/2, or 1/8. Your net mineral acres are 80 × 1/8 = 10.
Step 2: Decimal interest
Most Marcellus and Utica wells are drilled in units that combine many tracts. Your royalty is based on your share of the unit:
Decimal interest = net mineral acres ÷ unit acres × royalty rate
Example: 10 net mineral acres in a 640-acre unit with an 18% royalty gives 10 ÷ 640 × 0.18 = 0.00281250.
Step 3: Monthly royalty
Multiply the unit’s monthly sales by your decimal. If the unit sells 300,000 Mcf of gas at $2.50 per Mcf, sales are $750,000. With a decimal of 0.00281250, the gross royalty is $2,109.38 for that month, before any deductions.
The Pennsylvania minimum royalty and deductions
Pennsylvania’s Guaranteed Minimum Royalty Act requires most oil and gas leases to pay the landowner at least one-eighth (12.5%) royalty. In Kilmer v. Elexco Land Services (2010), the Pennsylvania Supreme Court held that the one-eighth can be measured at the well, after post-production costs are deducted. Whether your operator can deduct gathering, processing and transportation costs depends on your lease language. Many newer leases limit or forbid those deductions.
If your checks show large deductions your lease does not seem to allow, our royalty dispute attorneys can review the lease and the statements.
When your numbers do not match
A difference between this calculator and your check stub is common. It can come from:
- A different unit size than you expected, or a tract that is only partly in the unit
- A title question, such as an old reservation of oil and gas rights, which a title opinion can resolve
- Price differences, including regional gas prices that are lower than headline prices
- Deductions, taxes or fees shown on the stub
- Production that changes month to month, especially in the first years of a shale well
If the decimal on your division order looks wrong, ask for an explanation before you sign it.
Common questions
What is a good royalty rate in Pennsylvania?
The legal minimum is 12.5%. Rates offered in southwestern Pennsylvania vary with location, the operator and lease terms. The rate is only part of the picture. Deduction language, the bonus and the term all affect what you receive. Have a lease reviewed before you sign.
Why did my royalty check drop?
Shale wells usually produce the most in their first months and then decline. Gas prices also change. A sudden drop can also come from new deductions, a change in ownership records, or a well that was shut in.
Do I pay tax on royalties?
Royalty income is generally taxable income. Talk with your accountant about how to report it. If you inherit mineral rights, Pennsylvania inheritance tax may also apply. Our PA inheritance tax calculator gives an estimate.
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