What it means
In business and accounting, natural resources represent the raw materials that fuel commercial operations. Unlike buildings or machinery, which are man-made, these are gifts from the earth.
They include anything from crude oil beneath the seabed to trees in a commercial forest and gravel in a quarry. Because these assets physically diminish as they are extracted, accounting rules require companies to measure this reduction carefully.
This process is known as depletion. Depletion is the economic twin of depreciation, but instead of wearing out from use, the asset physically disappears piece by piece.
Understanding how to value and write down natural resources is crucial for managers because it directly impacts both the balance sheet and the yearly profit statement. When a company buys land containing these assets, the purchase cost must be spread out over the estimated total amount of the resource.
As each ton or barrel is extracted, a portion of the original asset cost is moved into the operating expenses for that period. This ensures that the financial statements accurately reflect the true cost of generating revenue.
For non-finance managers, keeping a close eye on resource valuation helps in budgeting for future land purchases, managing cash flow, and understanding tax obligations associated with extraction industries. Think of a natural resource like a large jar of sweets.
Every time you take a sweet out, the total value and volume of the jar go down until eventually, nothing is left.
In practice
Real-world examples
Example 1
GreenTimber Co. purchased a forest for $500,000, estimated to hold 100,000 timber logs. As they cut down 10,000 logs in their first year, they record $50,000 of depletion expense.
Example 2
AquaPure Ltd bought a mineral spring site for $200,000, containing an estimated 1 million litres of spring water. Extracting 100,000 litres in year one creates a depletion cost of $20,000.
Example 3
A small quarry business in Yorkshire acquired mineral rights for $300,000, holding 150,000 tonnes of aggregate. Selling 30,000 tonnes this year results in a depletion charge of $60,000.
Think of it
Think of a natural resource like a large jar of sweets. Every time you take a sweet out, the total value and volume of the jar go down until eventually, nothing is left.
Formula
Calculation
Depletion Rate per Unit = (Total Cost of Resource - Residual Value) / Total Estimated Units
Annual Depletion Expense = Depletion Rate per Unit x Units Extracted in the Year
Worked example: a company pays $1,000,000 for an oil field, expects it to be worth $100,000 as land once extraction ends, and estimates the field holds 900,000 barrels.
1. Depletable amount = $1,000,000 - $100,000 = $900,000
2. Rate = $900,000 / 900,000 barrels = $1 per barrel
3. If 50,000 barrels are extracted this year, depletion expense = 50,000 x $1 = $50,000
At the year end the asset's carrying amount on the balance sheet falls from $1,000,000 to $1,000,000 - $50,000 = $950,000.Case study
Seen in the real world
This is a fictional, illustrative scenario. TerraRock Quarries purchased a limestone deposit in Derbyshire for $1,200,000, with an estimated yield of 2,000,000 tonnes of usable stone. The land itself is expected to have a residual value of $200,000 once extraction finishes. During its first year of trading, the company successfully extracted and sold 200,000 tonnes of limestone.
To calculate the depletion expense for the year, the finance manager first subtracts the residual land value from the initial purchase price, leaving $1,000,000 to be depleted. Dividing this by the total estimated yield of 2,000,000 tonnes gives a depletion rate of $0.50 per tonne. Multiplying this rate by the 200,000 tonnes extracted during the year results in a depletion expense of $100,000. This figure is recorded on the income statement, reducing taxable profit, while the asset account on the balance sheet is reduced by the same amount.
In year two a new geological survey cut the estimate of remaining usable stone from 1,800,000 tonnes to 1,500,000 tonnes. The remaining depletable amount was $1,200,000 - $100,000 - $200,000 = $900,000, so the new rate became $900,000 / 1,500,000 = $0.60 per tonne. Extracting 250,000 tonnes then produced a depletion expense of $150,000. By updating its estimates, TerraRock avoids overstating its profits and ensures proper tax compliance.
Watch out
Common mistakes
- Treating natural resources like standard buildings and using fixed-line depreciation instead of units-of-production depletion.
- Forgetting to subtract the residual value of the land after the resource has been completely extracted.
- Failing to update total estimated reserves when new geological surveys reveal higher or lower quantities than originally expected.
Questions
People also ask
What is the difference between depreciation and depletion?
Depreciation applies to man-made assets like machinery that wear out over time. Depletion applies to natural resources that physically diminish in quantity as they are extracted.
Are natural resources classed as current or non-current assets?
They are classed as non-current assets, specifically property, plant, and equipment or tangible fixed assets, because they provide economic benefits over multiple years.
What happens to the land after all the natural resources are gone?
The land remains on the balance sheet at its residual or salvage value. Any future use or sale of the empty land is accounted for separately.