# Decimal interest calculation for an oil lease
**URL:** https://www.mineralrightsforum.com/t/decimal-interest-calculation-for-an-oil-lease/47149
**Category:** Oil and Gas Leasing Help
**Created:** [June 12, 2019, 12:41am UTC](https://www.mineralrightsforum.com/t/decimal-interest-calculation-for-an-oil-lease/47149 "2019-06-12T00:41:40Z")
**Posts on this page:** 10
**Page:** 1
### Author:  [@Allison\_Aldridge-Saur](https://www.mineralrightsforum.com/u/Allison_Aldridge-Saur)
#### Post date: [June 12, 2019, 12:41am UTC](https://www.mineralrightsforum.com/t/decimal-interest-calculation-for-an-oil-lease/47149/1 "2019-06-12T00:41:40Z")
I have gotten myself totally confused on my royalty rate calculation for a recent lease. I have 13.5 acres in Stephens County at 3/16th. On my lease agreement, it says the total acres are 320, but the section they filed for in their permit is 1280. How do I convert my 3/16th to a decimal? Thank you all so much!
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### Author:  [@Allison\_Aldridge-Saur](https://www.mineralrightsforum.com/u/Allison_Aldridge-Saur)
#### Post date: [June 12, 2019, 12:46am UTC](https://www.mineralrightsforum.com/t/decimal-interest-calculation-for-an-oil-lease/47149/2 "2019-06-12T00:46:15Z")
I guess I need to add that within the 320 acres, I own 1/8th. I do not know what that looks like within the 1280 acre section, however.
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### Author:  [@Michael\_Hutchison](https://www.mineralrightsforum.com/u/Michael_Hutchison)
#### Post date: [June 12, 2019, 1:19am UTC](https://www.mineralrightsforum.com/t/decimal-interest-calculation-for-an-oil-lease/47149/3 "2019-06-12T01:19:47Z")
Allison, the formula is your net acres divided by total acres in the section times your decimal royalty, i.e. 3/16 = .1875, 1/8 = .125. A section is usually 640 acres, so if it’s a 1280 acre unit you only get your share of production from the section you own in. I’m not clear on the 320 acres, is that your total ownership or was the unit originally spaced as 320 acres?
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### Author:  [@Allison\_Aldridge-Saur](https://www.mineralrightsforum.com/u/Allison_Aldridge-Saur)
#### Post date: [June 12, 2019, 1:27am UTC](https://www.mineralrightsforum.com/t/decimal-interest-calculation-for-an-oil-lease/47149/4 "2019-06-12T01:27:00Z")
I believe the 320 was the original spacing, but not sure!
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### Author:  [@TODD\_M\_Baker](https://www.mineralrightsforum.com/u/TODD_M_Baker)
#### Post date: [June 12, 2019, 1:36am UTC](https://www.mineralrightsforum.com/t/decimal-interest-calculation-for-an-oil-lease/47149/5 "2019-06-12T01:36:27Z")
Allison - using a 1280 acre unit, your calculations are as follows: 13.5 divided by 1280 times .1875 or 0.00197754.
If it is two 640 acre spaced units to form one production unit, your interest will be calculated differently due to your unit’s percentage of perforated wellbore feet to the total feet perforated.
Hope this helps.
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### Author:  [@TODD\_M\_Baker](https://www.mineralrightsforum.com/u/TODD_M_Baker)
#### Post date: [June 12, 2019, 1:41am UTC](https://www.mineralrightsforum.com/t/decimal-interest-calculation-for-an-oil-lease/47149/6 "2019-06-12T01:41:46Z")
The 320 acre figure on your lease is the gross acres that your 13.5 acres is under. The lease will stipulate the royalty.
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### Author:  [@Allison\_Aldridge-Saur](https://www.mineralrightsforum.com/u/Allison_Aldridge-Saur)
#### Post date: [June 12, 2019, 1:58am UTC](https://www.mineralrightsforum.com/t/decimal-interest-calculation-for-an-oil-lease/47149/7 "2019-06-12T01:58:49Z")
Todd, your two responses left me still a bit uncertain. My lease states 320 acres at 3/16ths. It sounds like the decimal you gave is what I should use in estimating what the well worth range could be over the years?
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### Author:  [@Allison\_Aldridge-Saur](https://www.mineralrightsforum.com/u/Allison_Aldridge-Saur)
#### Post date: [June 12, 2019, 2:05am UTC](https://www.mineralrightsforum.com/t/decimal-interest-calculation-for-an-oil-lease/47149/8 "2019-06-12T02:05:44Z")
Do if it is in 640 acres, is it twice the royalty amount, is what I wanted to ask.
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### Author:  [@Buddy\_Cotten](https://www.mineralrightsforum.com/u/Buddy_Cotten)
#### Post date: [June 12, 2019, 8:34pm UTC](https://www.mineralrightsforum.com/t/decimal-interest-calculation-for-an-oil-lease/47149/9 "2019-06-12T20:34:18Z")
If the 320 acres is all contained within the 1280-acre spacing unit, then the formula would be:
(Net acres/1280) \* (3/16)
Best,
Buddy Cotten
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### Author:  [@MRFAdmin\_SV](https://www.mineralrightsforum.com/u/MRFAdmin_SV)
#### Post date: [January 11, 2025, 7:26pm UTC](https://www.mineralrightsforum.com/t/decimal-interest-calculation-for-an-oil-lease/47149/10 "2025-01-11T19:26:46Z")