Installment Sale Calculator (Form 6252) 2026
Estimate your IRS Form 6252 installment sale tax for 2026. Calculates gross profit percentage, current-year gain to recognize, depreciation recapture (taxed in Year 1 even if no payment received), AFR interest on the deferred portion, and a year-by-year capital gains projection. Free, private, runs entirely in your browser.
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| Year | Principal | Gain | LTCG + NIIT | Imputed Interest |
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Source: IRS Publication 537 — Installment Sales + Form 6252 instructions 2026 (irs.gov). Last updated: May 3, 2026.
What Is an Installment Sale (Form 6252)?
An installment sale, reported on IRS Form 6252, is a sale of property where the seller receives at least one payment after the year of sale. Section 453 of the Internal Revenue Code lets the seller defer capital gains tax across the years payments are received instead of recognizing the entire gain in the year of sale. Common uses include seller-financed real estate, business buyouts, and family-to-family asset transfers. The installment method is mandatory unless you elect out on a timely-filed return. Source: IRS Publication 537.
Each year you receive a payment, the principal portion is split into return of basis (tax-free) and gain (taxable). The percentage that is gain — the gross profit percentage — is fixed at the start of the contract: gross profit ÷ contract price. So if your gross profit is 60% of the contract price, then 60 cents of every dollar of principal received is taxable gain. Stated interest is reported separately each year as ordinary interest income. Last updated: May 3, 2026.
How the Calculation Works in 2026
Form 6252 follows a fixed sequence: (1) selling price minus selling expenses minus adjusted basis minus depreciation recapture = gross profit; (2) gross profit ÷ contract price = gross profit percentage; (3) principal received in the year × gross profit percentage = installment sale income for the year. Depreciation recapture under IRC § 1245 (personal property) and § 1250 (real estate) is fully recognized in the year of sale at ordinary rates — it is not deferred under the installment method. This is the most common surprise for sellers of rental real estate or depreciated business assets, who often assume the entire tax bill spreads evenly.
The tool above runs the IRS Pub 537 sequence: it deducts recapture from gross profit before computing the installment percentage, taxes recapture at your ordinary rate in Year 1, and then applies your long-term capital gains rate (0/15/20%) plus 3.8% NIIT (if applicable) to the deferred portion across the contract term. It also shows imputed interest at the AFR you supply — the minimum stated rate the IRS accepts under IRC § 1274 / § 7872.
When Installment Sales Are a Good Tax Strategy
Spreading gain across multiple tax years is most valuable when (a) the seller would jump from a 15% LTCG bracket to 20% or trigger NIIT in the year of sale, (b) the seller has a one-time income spike (sale of a business, retirement) and expects lower brackets in future years, or (c) the seller wants ongoing interest income at AFR rates from a buyer they know and trust. Real estate flippers and dealers cannot use the installment method — it is restricted to investment, personal, and business property held for productive use. Publicly traded stock is also ineligible.
Watch for the pledge rule: if you pledge the installment note as collateral for a loan exceeding $150,000 of contract price, the loan proceeds are treated as a payment, accelerating the gain. Also watch the related-party second-disposition rule — if a related-party buyer resells the property within two years, your full deferred gain accelerates immediately. Form 6252 Part III handles related-party reporting.
Imputed Interest and the Applicable Federal Rate (AFR)
If the installment contract states no interest, or interest below the applicable federal rate (AFR), the IRS will impute interest under IRC § 1274 and § 7872. Imputed interest reclassifies a portion of each principal payment as interest income, which is taxed at ordinary rates and shrinks the capital gain. The AFR is published monthly by the IRS — short-term (≤3 years), mid-term (3–9 years), and long-term (>9 years) rates apply based on the contract length. For 2026, mid-term AFRs are roughly in the 4.0–4.5% range; check the latest IRS Revenue Ruling for the month your contract is signed. Charging at least the AFR avoids imputed interest and keeps your gross profit percentage clean.
Frequently Asked Questions
What is IRS Form 6252?
Form 6252 (Installment Sale Income) is the IRS form used to report income from the installment method of accounting under IRC § 453. It applies any time you sell property and receive at least one payment after the year of sale, letting you spread capital gains tax across the years you receive payments instead of recognizing all the gain in the year of sale.
How is the gross profit percentage calculated?
Gross profit percentage = (sale price − adjusted basis − selling expenses − depreciation recapture) ÷ contract price. This percentage is fixed for the life of the contract. Each year, the principal portion of payments received is multiplied by the gross profit percentage to compute the taxable installment sale income.
Why is depreciation recapture taxed in Year 1, not deferred?
IRC § 453(i) explicitly excludes depreciation recapture under § 1245 (personal property) and § 1250 (real estate) from the installment method. The full recapture amount must be recognized in the year of sale at ordinary income rates, even if no cash payment was received in that year. This is the most common surprise for sellers of rental real estate.
What happens if my interest rate is below the AFR?
If the stated interest is below the applicable federal rate (AFR), the IRS imputes interest under IRC § 1274 and § 7872. Imputed interest reclassifies part of each principal payment as ordinary interest income, which lowers the capital gain portion and increases your tax bill. To avoid this, charge at least the AFR for the contract term (short-term ≤3 years, mid-term 3-9 years, long-term >9 years).
Can a real estate dealer or stock seller use the installment method?
No. Real estate dealers (people who hold property as inventory) and sellers of publicly traded securities cannot use the installment method. The election is restricted to investment property, personal-use property, and property held for productive use in a trade or business. A casual flipper of one or two houses may qualify; a habitual flipper does not.
What is the related-party second-disposition rule?
IRC § 453(e) accelerates all deferred gain if the original buyer is a related party (family, controlled entity) and they resell the property within 2 years of the original sale. The seller must recognize the remaining deferred gain immediately. This anti-abuse rule prevents using a related-party intermediary to defer gain on what is really a sale to a third party.
How does the pledge rule affect installment sales?
IRC § 453A imposes a pledge rule: if the seller pledges the installment note as collateral for a loan, the loan proceeds are treated as a payment, accelerating the gain. This applies only to non-dealer sales over $150,000. There is also an interest charge under § 453A on the deferred tax for installment notes over $5 million per year per taxpayer.