Federal Section 280A Vacation Home Rental Classification + Deduction Calculator

How this calculator works

IRC § 280A is the federal tax rulebook for any dwelling unit that is both a personal residence AND rented to third parties during the tax year. The classification — Augusta Rule, Residence, or Rental Property — turns on two day-counts: total days rented at fair rental and total days of personal use. The classification then drives whether the rental income is included in gross income, whether deductions are capped at rental income or uncapped, what carryforward (if any) is available for disallowed expenses, and how Schedule E reports the activity.

This calculator runs the day-count classification, allocates expenses between personal and rental use using the IRS total-days method, applies the three-tier deduction stack under Treas. Reg. § 1.280A-3(d), surfaces the carryforward of disallowed expenses for the residence classification, and gives an optimization recommendation showing which day-count lever would change the classification. The output tells the owner (and the CPA preparing Schedule E) the deductible expense limit, the net taxable rental income or loss, and the planning move that would change the tax story.

The 26 USC § 280A framework

§ 280A(a) is the starting point — a general DISALLOWANCE of all deductions allocable to a dwelling unit used by the taxpayer during the year as a residence. § 280A(b) carves out the normally-allowable deductions (e.g., mortgage interest on the primary residence under § 163(h), property tax under § 164) so that the general disallowance does not strip away deductions that would be available without regard to the rental activity.

§ 280A(c) and § 280A(d) define when the dwelling counts as a RESIDENCE — when the taxpayer's personal use during the year exceeds the GREATER OF 14 DAYS OR 10% of the number of days the unit was rented at fair rental. If the dwelling is a residence under this test, § 280A(c)(5) caps deductions for the rental activity at the gross rental income from the unit — no deductible loss can be generated, and excess allocable expenses carry forward to next year under § 280A(c)(5)(C).

§ 280A(g) is the Augusta Rule — a narrow but powerful exception for personal residences rented FEWER THAN 15 DAYS during the year. Under § 280A(g), the entire year's rental income is EXCLUDED from gross income, and no rental deductions are allowed. The cliff is binary at day 15 — 14 days at any rate = tax-free; 15 days = entire year includible.

The three classifications (Augusta, Residence, Rental Property) are mutually exclusive and exhaust the universe of mixed-use scenarios under § 280A. The calculator runs the day-count tests in the statute's order: Augusta Rule first (rental days under 15), then residence (personal use over the threshold), then rental property (default for 15+ rental days with personal use within the threshold).

Inputs explained

Days rented at fair rental is the count of days the unit was rented to third parties at a fair rental rate under § 280A(d)(3). Days rented to family members at less than fair rental count as PERSONAL use, not rental use. The 15-day Augusta cliff applies here; the 14-day / 10% personal-use threshold uses this count as the denominator for the 10% prong.

Days of personal use is the count of days the taxpayer, co-owners, family members, swap partners, or others paying less than fair rental used the unit. The critical carve-out under § 280A(d)(2) is that days spent CLEANING OR MAINTAINING the unit (and not also using it for personal purposes) do NOT count as personal use. Keep contemporaneous logs of cleaning and maintenance days separately from personal-use days — this is the single most powerful planning lever near the threshold.

Gross rental income is the total rent collected during the year. For the Augusta Rule, the entire amount is excluded under § 280A(g); for residence classification, it caps the allowed deductions under § 280A(c)(5); for rental-property classification, it is the gross-receipts line on Schedule E.

Mortgage interest, property tax, depreciation, repairs, and utilities are entered as FULL-YEAR TOTALS. The calculator allocates between personal and rental use using the IRS total-days method (rental days / total days used). The Bolton method (rental days / 365 for interest+tax only) is documented in the strategy note and is available to taxpayers who want to maximize the total deductible expense over the life of the property in the residence classification.

Key thresholds and gotchas

The 15-day Augusta cliff is BINARY. There is no proration at day 14 or day 15 — 14 rental days at any rate excludes the entire year's rent under § 280A(g); 15 rental days transitions the entire year's rent to includible-income status. Plan rental dates carefully if you are managing toward the cliff.

The 14-day / 10% personal-use threshold is a tax cliff in the opposite direction. Crossing it by even 1 day flips the classification from rental property (uncapped deductions, potential loss) to residence (deductions capped at rental income, excess carryforward only). Use the cleaning/maintenance carve-out under § 280A(d)(2) to preserve rental-property classification — days documented as cleaning/maintenance do not count toward personal use.

The three-tier deduction order under Treas. Reg. § 1.280A-3(d) matters because lower-tier deductions (depreciation, in Tier 3) are the most likely to be CAPPED OUT. Tier 1 (interest + tax) and Tier 2 (operating expenses) usually fit within the rental-income cap; Tier 3 (depreciation) is what spills into the carryforward bucket. The carryforward retains its tier character — a Tier 3 carryforward in year 1 is still Tier 3 next year and is subject to the same per-year cap.

The Bolton method (rental days / 365 for interest+tax) frees additional Tier 2/3 capacity for residence-classified taxpayers. It is well-established in the Ninth and Tenth Circuits (Bolton v. Commissioner; McKinney v. Commissioner) and accepted by the Tax Court. The IRS continues to advocate the total-days method on Form 8825 instructions but does not litigate Bolton aggressively. For a residence-classified taxpayer where the cap is binding, computing both methods and adopting the more favorable one (typically Bolton) is standard practice — but disclose the method on the return.

Personal use by family members is the most-overlooked § 280A trap. § 280A(d)(2)(C) treats use by family members (spouse, siblings, ancestors, lineal descendants) as PERSONAL USE regardless of payment — unless the family member uses the unit as their PRINCIPAL RESIDENCE and pays a FAIR RENTAL. The "free week for the in-laws" or "discounted rate for the sister" almost always counts toward the personal-use day count and can push a property over the residence-classification threshold.

Short-term hotel-like rental (substantial services provided to guests — daily cleaning, meals, concierge) can convert the activity from a rental to a § 162 trade or business under Rev. Rul. 57-108, which moves the income from Schedule E to Schedule C and may subject it to self-employment tax. § 280A still applies to the day-count classification, but the SE-tax exposure changes the planning calculus significantly.

What this calculator does NOT model

The IRC § 469 passive activity loss limitations are not applied at the rental-property classification. The calculator computes the gross net rental income/loss; the user should run that result through the § 469 stack separately (active-participation $25K allowance under § 469(i), real-estate-professional exception under § 469(c)(7), suspended-loss release on disposition under § 469(g)).

The Bolton interest/tax allocation method is documented in the strategy note but is not computed as an alternative output. For taxpayers in the residence classification where the cap is binding, run the calculator twice — once with the supplied interest/tax inputs (IRS allocation) and once with the interest/tax inputs scaled by rental-days-over-365 (manually approximating Bolton) — to see the maximum additional Tier 2/3 deduction available.

State income tax is not modeled. Most states with income taxes conform to § 280A by reference to federal AGI; California and a few others have idiosyncratic adjustments. Confirm conformity in the property's state.

Self-employment tax is not modeled. Long-term rental of a dwelling unit is generally not subject to SE tax under IRC § 1402(a)(1) (real-estate rental exception); short-term hotel-like rental with substantial services may be subject to SE tax under Rev. Rul. 57-108. Confirm the character of the activity before relying on the rental-property classification's gross net income figure.

Multi-year carryforward tracking is reported as a single-year dollar figure for the residence classification's combined Tier 2/3 carryforward. Actual carryforward utilization in future years depends on next year's classification, rental income, and allocable expense stack — the calculator does not project forward beyond the single-year dollar figure.

QBI deduction (IRC § 199A) interaction is not modeled. A short-term rental that rises to the level of a trade or business under the § 199A safe harbor (Rev. Proc. 2019-38) may qualify for the 20% QBI deduction on Schedule E income — separate analysis required.

Sources

IRC § 280A(a) is the general disallowance rule. IRC § 280A(b) carves out otherwise-allowable deductions. IRC § 280A(c) covers exceptions including the rental-use exception. IRC § 280A(c)(5) is the rental-income deduction cap and carryforward mechanic. IRC § 280A(d) defines residence use and the 14-day / 10% personal-use threshold. IRC § 280A(d)(2) is the cleaning/maintenance day carve-out. IRC § 280A(g) is the Augusta Rule (fewer than 15 rental days).

IRC § 469 is the passive activity loss limitation stack. IRC § 469(i) is the $25,000 active-participation rental allowance with the $100K-$150K MAGI phaseout. IRC § 469(c)(7) is the real-estate-professional exception. IRC § 1402(a)(1) is the SE-tax exception for real-estate rental. Rev. Rul. 57-108 covers short-term hotel-like rental with substantial services subject to SE tax.

Treas. Reg. § 1.280A-3 spells out the allocation regulations, including the three-tier deduction stack under § 1.280A-3(d) and the carryforward mechanics under § 1.280A-3(e).

Bolton v. Commissioner, 77 T.C. 104 (1981), aff'd 694 F.2d 556 (9th Cir. 1982), and McKinney v. Commissioner, 732 F.2d 414 (10th Cir. 1984), establish the alternative interest/tax allocation method using rental days over 365 calendar days.

IRS Form 8825 reports rental real estate income for partnerships and S corps. IRS Schedule E (Form 1040) reports supplemental income from rental real estate at the individual level. IRS Publication 527 is the official Residential Rental Property guide.