Calculate the lease liability as the present value of the lease payments not yet paid, discounted at the rate implicit in the lease or, if that is not readily determinable, your incremental borrowing rate. Then build the right-of-use asset from it: lease liability, plus any payments made at or before commencement, plus initial direct costs, less lease incentives received. Those two formulas are ASC 842-20-30-1 and ASC 842-20-30-5, and everything else is assembling the inputs correctly.
The arithmetic takes a minute. The part that takes a week is deciding which payments belong in the schedule, which options extend the term, and what the landlord actually agreed to pay for. This guide works one realistic office lease end to end, with escalations, three months of free rent and a tenant improvement allowance, so you can check your own model against numbers that tie.
The two formulas
Under ASC 842 the lessee books two balances at commencement, and one drives the other.
Lease liability equals the present value of the lease payments not yet paid at the commencement date. Payments already made by that date are excluded, which matters more than it sounds like it should on real estate leases where rent is paid in advance.
Right-of-use asset equals that lease liability, plus lease payments made to the lessor at or before commencement, plus initial direct costs incurred, less lease incentives received. In symbols: ROU = liability + prepayments + IDC − incentives.
Both classifications use the same two formulas. Whether the lease turns out to be operating or finance changes how the balances unwind afterwards, not how they start. If you need the subsequent entries, the ASC 842 journal entries page works both patterns with full schedules, and the ASC 842 disclosure requirements page shows where these balances end up in the footnote.
Step 1: build the payment vector
This is the step that decides whether the answer is right. ASC 842 has a specific view of what counts as a lease payment, and it is narrower than the total cash you will send the landlord.
| Goes into the present value | Stays out |
|---|---|
| Fixed base rent, including every scheduled escalation | Variable payments based on usage or sales volume |
| In-substance fixed payments, such as a floor inside a percentage rent clause | CAM, real estate taxes and insurance that vary with actual cost |
| Index-linked payments, measured at the index in effect at commencement | Future increases in that index, until a remeasurement is triggered |
| Payments in optional periods you are reasonably certain to exercise | Optional periods you are not reasonably certain to exercise |
| A purchase option price you are reasonably certain to pay | Purchase options unlikely to be exercised |
| Termination penalties, unless the term already assumes you stay | Payments for goods or services you supply to the landlord |
| Amounts probable of being owed under a residual value guarantee | The full guaranteed amount, if not probable of being owed |
An index-linked escalation is the one people most often overstate. A clause tying rent to CPI is measured using the index at commencement and held flat from there. You do not forecast inflation into the schedule. A fixed 3 percent annual step, by contrast, is fully capitalized because it is knowable on day one.
Two housekeeping points before you leave this step. First, a free rent period is a zero payment in the vector, not a deduction anywhere else. Second, scope the population before you scope the payments: leases hide inside contracts that are not called leases, and the reliable way to find them is to work a full year of recurring vendor payments rather than the lease register. If a large share of that recurring spend is cloud and managed IT, a read-only view of recurring cloud and SaaS commitments makes the contracts worth reading easy to spot.
Step 2: choose the discount rate
Use the rate implicit in the lease when it is readily determinable. On commercial property it almost never is, because you would need the landlord's fair value of the asset and its estimated residual, and no landlord shares either. So most lessees fall back to the incremental borrowing rate: the rate you would pay to borrow, on a collateralized basis, an amount equal to the lease payments, over a similar term, in a similar economic environment.
Three practical notes. Match the rate to the lease term, not to your revolver. A 10 year lease discounted at a 3 year borrowing rate understates the liability. Support the rate with something written down, because auditors ask for the derivation more often than they ask for the arithmetic. And private companies may elect a risk-free rate by class of underlying asset, which removes the derivation work but produces a larger liability, since a lower rate discounts the payments less.
Step 3: present-value the payments
With escalations in the schedule, Excel's PV function will not do it, because PV assumes a level payment. Lay the payments out one per period and discount each one individually, then sum. For a payment at period t, divide it by (1 + r)t, where r is the periodic rate.
For monthly leases, nearly every lease accounting platform uses the annual rate divided by twelve rather than compounding to an effective monthly rate. It is worth confirming which convention your system applies before you reconcile a spreadsheet to it, because the two answers differ by a small amount that widens as the term lengthens.
Timing convention matters just as much. Rent paid in advance means the period one payment happens at t equals zero. It is therefore paid at commencement, excluded from the liability, and added to the right-of-use asset instead. Rent in arrears puts the first payment at t equals one, and it is in the liability. Getting this backwards shifts the liability by roughly one month's rent, which is the single most common reconciliation gap between a homemade model and a platform.
A worked example, start to finish
A 1,500 rentable square foot office suite. Five year term, commencing March 1, 2026. Base rent starts at $32.00 per square foot per year, or $4,000 per month, escalating 3 percent on each anniversary. The first three months are abated. The landlord pays a $50,000 tenant improvement allowance on the commencement date for improvements the tenant will own. Rent is payable in advance on the first of each month. No renewal option is reasonably certain of exercise. Incremental borrowing rate: 8 percent.
| Lease year | Monthly rent | Months paid | Cash for the year |
|---|---|---|---|
| 1 | $4,000.00 | 9 (three abated) | $36,000.00 |
| 2 | $4,120.00 | 12 | $49,440.00 |
| 3 | $4,243.60 | 12 | $50,923.20 |
| 4 | $4,370.91 | 12 | $52,450.92 |
| 5 | $4,502.04 | 12 | $54,024.48 |
| Total | 57 | $242,838.60 |
Discount those 60 monthly amounts at 8 percent divided by twelve, remembering that the March 1, 2026 payment is zero and is made at commencement anyway. The present value of everything still owed comes to $197,956.38. That is the lease liability.
The right-of-use asset starts from the same figure. There are no initial direct costs here and no rent paid at commencement, since month one is abated, so the only adjustment is the incentive: $197,956.38 less the $50,000 allowance received on day one gives a right-of-use asset of $147,956.38.
| Account | Debit | Credit |
|---|---|---|
| Right-of-use asset | $147,956.38 | |
| Cash (allowance received) | $50,000.00 | |
| Lease liability | $197,956.38 |
Assume the lease is operating, which a five year office suite almost always is. Straight-line lease cost is total payments of $242,838.60 less the $50,000 incentive, divided by 60 months: $3,213.98 per month, or $38,567.72 a year.
What happens during the free rent months
Here is the result that makes people rebuild their spreadsheet, wrongly. Interest accretes on the liability every month whether or not you pay rent, so during an abated period the lease liability rises.
| Month | Liability, start | Interest | Payment | Liability, end | ROU amortization | ROU asset, end |
|---|---|---|---|---|---|---|
| Mar 2026 | $197,956.38 | $1,319.71 | $0.00 | $199,276.09 | $1,894.27 | $146,062.11 |
| Apr 2026 | $199,276.09 | $1,328.51 | $0.00 | $200,604.60 | $1,885.47 | $144,176.64 |
| May 2026 | $200,604.60 | $1,337.36 | $4,000.00 | $197,941.96 | $1,876.62 | $142,300.02 |
The liability peaks at $201,941.96 on June 1, just before the first cash rent hits, having climbed $3,985.58 above where it started. That is correct. The abatement was already priced into the present value as three zero payments, and the balance simply compounds until cash starts flowing.
Note also that the May payment column shows $4,000 arriving in the month labeled May, because rent is paid in advance on June 1 and that payment settles the balance carried out of May. Whichever convention your schedule uses, keep it consistent between the interest column and the payment column or the balances will drift by exactly one month of interest.
The journal entry for March 2026 is a debit to operating lease cost of $3,213.98, a credit to the right-of-use asset of $1,894.27, and a credit to the lease liability of $1,319.71. No cash moves, because rent is abated. Under ASC 840 that gap would have built a deferred rent balance. There is no deferred rent account under ASC 842; the timing difference lives inside the right-of-use asset now.
Five errors that produce a wrong liability
- Using the wrong start date. The measurement runs from the commencement date, which is when the landlord makes the space available. That is often neither the execution date nor the rent commencement date, and it shifts the whole schedule.
- Abstracting from the original lease only. A third amendment that reset the rent or extended the term makes every number above wrong. Missing amendments cause more restatements than any calculation error.
- Treating free rent as an incentive. It is not. No cash moves from landlord to tenant, so it is a zero payment inside the present value, and deducting it from the ROU asset counts it twice. The lease incentives under ASC 842 guide works through the distinction.
- Netting the allowance against leasehold improvements. A tenant improvement allowance for tenant-owned improvements reduces the right-of-use asset. The improvements themselves stay capitalized at gross cost and amortize over the shorter of useful life or remaining lease term.
- Deciding options by default. Including or excluding a renewal option without a documented reasonably-certain assessment is the request auditors push on hardest, because adding a five year option onto a five year base term roughly doubles the payment stream and the liability with it.
Frequently asked questions
How do you calculate lease liability under ASC 842?
Present-value the lease payments not yet paid at the commencement date, using the rate implicit in the lease when it is readily determinable and the incremental borrowing rate when it is not. Include fixed and in-substance fixed payments, index-linked payments at the index in effect on day one, and payments in optional periods you are reasonably certain to exercise.
How do you calculate the lease liability and right-of-use asset together?
Calculate the liability first, since the asset is built from it. Right-of-use asset equals the lease liability, plus any lease payments made at or before commencement, plus initial direct costs, less lease incentives received. With no prepayments, no initial direct costs and no incentives, the two balances are equal at commencement.
How do you calculate lease liability in Excel?
Lay each payment out in its own row against a period number, then discount each one by dividing it by (1 + r)t and sum the column. Excel's PV function only works when every payment is identical, so it fails on any lease with escalations. Use XNPV instead if you want to discount on actual dates rather than even periods.
Is the right-of-use asset always equal to the lease liability?
Only when there are no prepaid rents, no initial direct costs and no lease incentives. Any of those three breaks the equality at commencement. On a lease with rent paid in advance the ROU asset is higher by the day-one payment; on a lease with a large tenant improvement allowance it is lower, sometimes by a lot.
What discount rate should I use for the lease liability?
The rate implicit in the lease if you can determine it, which on real estate you generally cannot because it requires the landlord's asset fair value and residual estimate. Otherwise use your incremental borrowing rate, matched to the lease term and on a collateralized basis. Private companies may elect a risk-free rate by class of underlying asset, at the cost of a larger recognized liability.
Do you include CAM and property taxes in the lease liability?
Not when they vary with actual cost, which is the normal arrangement. Variable payments are expensed as incurred. They do get included if you elected the practical expedient not to separate lease and non-lease components, or if the clause sets a fixed amount rather than a reconciled one, which makes it an in-substance fixed payment.
Does the lease liability change after commencement?
It unwinds on a schedule, accreting interest and reducing with payments, without being recalculated. A full remeasurement happens only on a specific trigger: a change in the term or purchase option assessment, a change in amounts probable under a residual value guarantee, or a modification not accounted for as a separate contract.
Where the inputs come from
Every number in the example above except the discount rate came out of a lease document: the commencement date, the rent schedule with its escalations, the abatement months, the allowance and who owns the resulting improvements. Lease accounting software calculates faultlessly from whatever you import, which is precisely the risk when the import came from a fast read of the original lease and missed an amendment.
Upload a lease and its full amendment chain and our AI returns the ASC 842 input set with every field linked back to the page and clause it came from, so the schedule you build is one you can defend line by line. If you are adopting the standard for the first time, the ASC 842 implementation guide covers building the lease population and electing the expedients, and the ASC 842 journal entries page carries the entries and schedules for both lease classifications.