Tenant Security Deposit Statutory Interest Calculator
Work out the interest a landlord owes a tenant at lease end, period by period, using each year’s published rate — Chicago, San Francisco, Maryland, Massachusetts and more, with a printable audit trail.
Verify every rate before you rely on it. Rates are reset annually by each jurisdiction and the values here are seeded from published figures, not a live feed. Coverage rules, exemptions and deadlines also vary by building size and lease date. This is an estimate, not legal advice — confirm with the issuing agency or a landlord-tenant attorney.
| Period | From – To | Rate | Portion | Interest |
|---|
Simple interest on $2,400, no compounding. Keep this schedule with the itemized statement — showing the math is what defeats a deposit claim.
How to use the security deposit interest calculator
Enter the deposit, the dates it was held, and where the property is. The calculator splits the tenancy into accrual periods, applies the rate published for each one, and returns the interest owed, the total to return, the deadline to return it by — and a period-by-period schedule you can hand to the other side.
Enter the deposit and dates
Everything held as a deposit — pet, move-in, cleaning — plus the date it was received and the date the tenancy ended.
Pick the jurisdiction
Chicago, Illinois, San Francisco, Maryland, Massachusetts, New York, Minnesota, New Jersey, or custom rules you set yourself.
Check every rate row
Each accrual year gets its own editable rate. Compare each one against the official notice and correct anything that differs.
Read the total and save the PDF
Interest owed, amount due, return deadline, exposure if unpaid, and a two-page audit trail showing the math.
How the interest is built, period by period
Statutory deposit interest is simple interest, one year at a time. The deposit never changes, but the rate does: each accrual period earns whatever rate the jurisdiction published for that year. Add the periods together and you have the number. What the calculator does is stop anyone from applying a single blended rate across a four-year tenancy and getting it wrong.
Worked example — $2,400 held in Chicago from 1 Jun 2022 to 31 May 2026
Four accrual periods, each at Chicago’s published 0.010%:
Years 1–3, full periods: $2,400 × 0.0001 = $0.24 each → $0.72
Year 4 runs 364 of 365 days, prorated: $0.24 × 0.99726 = $0.24
Total interest $0.96, so the amount due is $2,400.96 by 15 Jul 2026
Skip that 96 cents and the CRLTO exposure is twice the deposit — $4,800 — plus interest, attorney fees and court costs. The rate is trivial; the penalty is not.
Rates, deadlines and penalties at a glance
What each jurisdiction pays, how long the deposit has to be held before anything is owed, and what it costs to get it wrong. Every rate below is a seeded figure, not a live feed — confirm each one against the issuing agency before you rely on it.
| Jurisdiction | Rate basis | Interest owed | Effective a year |
|---|---|---|---|
| Illinois — state act | 0.005% | $0.48 | 0.005% |
| Chicago — CRLTO | 0.010% | $0.96 | 0.010% |
| Minnesota | 1.0% | $95.93 | 1.000% |
| San Francisco | 0.1% – 5.2% | $182.40 | 1.900% |
| Maryland | 1.5% floor – 4.79% | $299.56 | 3.122% |
| Massachusetts | 5.0% or bank rate | $360.00 | 3.752% |
A $2,400 deposit received 1 Jun 2022 and returned 31 May 2026, run through the calculator’s seeded rates. San Francisco and Massachusetts pay nothing for the final partial year, which is why their effective rates sit below their headline ones. New York and New Jersey are absent because neither sets a statutory rate — the tenant gets whatever the account actually earned.
| Jurisdiction | Held before interest is owed | Return deadline | Exposure if it goes unpaid |
|---|---|---|---|
| Chicago (CRLTO) | More than 6 months | 45 days | Twice the deposit plus interest, attorney fees and court costs |
| Illinois (25+ units) | More than 6 months | 45 days | Twice the deposit plus court costs and attorney fees |
| San Francisco | 12 months | 21 days | The unpaid interest itself; no separate late-payment penalty |
| Maryland | 6 months, deposit of $50+ | 45 days | Up to three times the withheld amount plus reasonable attorney fees |
| Massachusetts | 12 months, paid annually | 30 days | Three times the deposit plus interest, court costs and attorney fees |
| New York (6+ units) | No minimum; 1% admin fee allowed | 14 days | Loss of the right to retain any part of the deposit, plus possible punitive damages |
| Minnesota | 12 months | 21 days | The withheld amount plus a punitive award for bad-faith retention |
| New Jersey | No minimum; actual account earnings | 30 days | Double the wrongfully withheld amount plus court costs |
Coverage inside each jurisdiction is narrower than the headline suggests. Chicago exempts owner-occupied buildings of six units or fewer; the Illinois act only reaches buildings of 25 or more units; New York’s rule applies to buildings of six or more. Check that the unit is actually covered before calculating anything.
| Rate year | Published rate | On a $2,400 deposit |
|---|---|---|
| 2006 | 1.710% | $41.04 |
| 2008 | 1.260% | $30.24 |
| 2009 | 0.120% | $2.88 |
| 2011 | 0.073% | $1.75 |
| 2013 | 0.023% | $0.55 |
| 2015 – 2026 | 0.010% | $0.24 |
The CRLTO rate tracks bank deposit rates, which collapsed after 2008 and stayed there for ordinary savings products even as mortgage rates climbed. Chicago has published 0.010% every year since 2015. The Comptroller resets it each December, so a long tenancy can still straddle several different rates.
One deposit, one holding period, a 375-fold spread in what is owed. The deposit is not what drives the answer — the jurisdiction is, and inside it, which years the tenancy happened to span.
- A tiny amount is still a claim — Chicago’s 96 cents sits against statutory exposure of twice the deposit. Size of the interest has nothing to do with size of the penalty.
- The years matter as much as the place — a San Francisco tenancy spanning 2023–2025 earns several times what one spanning 2020–2022 earned, on the identical deposit.
- Partial years are a rule, not a rounding choice — some jurisdictions prorate the final stub by days, others pay nothing for it. That single setting moves Massachusetts by $120 here.
Everything the calculator works out
One deposit and two dates give you the interest, the settlement statement, the compliance deadlines, and a schedule that shows every period and rate used to get there — which is what actually settles a deposit dispute.
The figures behind the interest owed
*From the worked example — a $2,400 deposit received 1 Jun 2022 and returned 31 May 2026 under the CRLTO. Every figure recomputes for the deposit, dates and jurisdiction you enter.
Built for both sides of the deposit
The interest owed is a small number that decides a large one. Tenants use it to check the refund; landlords and managers use it to close out a tenancy without leaving a statutory claim on the table.
Working out whether the cheque that arrived actually includes the interest, and whether the itemized statement showed up inside the legal window.
- Interest is owed on the full deposit, deductions or not
- Include pet and move-in deposits in the amount
- Note the date the deposit was received, not the lease date
Settling the deposit correctly the first time, because the penalty for missing a dollar of interest is measured against the whole deposit.
- Check whether your building is even covered
- Where interest is annual, pay or credit it each year
- Keep the schedule with the itemized statement
Producing a defensible number per unit across several rate years, and handing owners something that survives a challenge.
- Re-check rates each December when they reset
- Save the PDF audit trail to the tenant file
- Watch the deadline clock from the move-out date
7 things to know about deposit interest
The assumptions that quietly turn a small payment into a statutory claim — and the checks that keep the number defensible.
Security deposit interest FAQ
The questions tenants and landlords ask most when a deposit is being settled and nobody is sure what the interest actually comes to.
In a number of states and cities, a landlord who holds a tenant’s security deposit has to pay the tenant interest on it for the time it was held. The rate is set by statute or published each year by a city agency — it is not something the landlord picks.
The interest belongs to the tenant whatever happens to the deposit itself. Even where the landlord lawfully deducts for unpaid rent or damage, the interest is calculated on the whole deposit that was held, not on what is left after deductions.
Simple interest, one accrual period at a time, each period using the rate published for that year. A full 12-month period earns deposit × rate. A final partial period is usually prorated by days, though some jurisdictions pay nothing for it.
Maryland works monthly instead: whole months elapsed are grouped by calendar year, and each group earns deposit × rate × months ÷ 12. Either way the interest is never compounded.
There is no federal rule — requirements are local. Chicago’s CRLTO, the Illinois act for buildings of 25 or more units, San Francisco, Maryland, Massachusetts, Minnesota, New Jersey and New York for buildings of six or more all require it in some form, and cities such as Los Angeles, Berkeley, Santa Monica and Washington DC publish their own rates.
Coverage inside a jurisdiction is narrower than people expect. Building size, owner occupancy and the lease date all change whether a unit is covered, so confirm the unit qualifies before calculating anything.
Yes. Deductions and interest are separate questions. The interest is earned on the deposit that was held during the tenancy, so lawful deductions come off the settlement at the end — they do not reduce the interest that accrued along the way.
The practical result is that a deposit can be fully consumed by deductions and the landlord can still owe the tenant the interest as a separate payment.
Because the CRLTO ties the rate to bank deposit rates, which collapsed after 2008 and never recovered for ordinary savings products. Chicago paid 1.71% for 2006 and has published 0.010% every year since 2015.
On a $2,400 deposit held four years that is about 96 cents. The penalty for not paying it did not shrink with the rate, which is exactly why it is worth calculating and documenting.
In most jurisdictions that require interest, failing to pay it is a statutory violation with damages far larger than the interest itself — commonly two or three times the deposit, plus the tenant’s attorney fees and court costs.
Chicago is the extreme case: 96 cents of unpaid interest on a $2,400 deposit can support a claim measured against twice the deposit plus fees. Pay it, or credit it against rent where the ordinance allows, and keep the schedule that shows the math.
No. Statutory deposit interest is simple interest everywhere in the U.S. Each accrual period earns interest on the original deposit only; interest already earned does not itself earn interest.
That matters over long tenancies — using a compound formula on a ten-year tenancy overstates what is actually owed.
It depends on the ordinance. Chicago requires payment or a rent credit within 30 days after the end of each 12-month period, not at move-out. Massachusetts is also annual. Others are settled with the deposit when the tenancy ends.
Where payment is annual, missed years do not disappear — they accumulate as unpaid interest and are still owed at the end, alongside whatever penalty attaches to having missed them.
Estimation Only — Not Legal Advice: This calculator estimates the statutory interest that may be owed on a residential security deposit, based entirely on the figures you enter. Rates are seeded from published values at the time of writing, not drawn from a live feed, and each jurisdiction resets its rate annually — every rate must be confirmed against the issuing agency’s official notice before it is relied on. Whether a tenancy is covered at all depends on building size, owner occupancy, unit type, the lease date and local exemptions, and rules differ between a state and the cities inside it. Return deadlines, itemization requirements, annual payment obligations and penalty multipliers also vary, and the figures shown for penalties are general descriptions of statutory exposure, not a prediction of any outcome. Nothing here is legal, tax or accounting advice, and no attorney-client relationship is created by using it. For informational purposes only; confirm rates, coverage and deadlines with the issuing agency or a landlord-tenant attorney before relying on any figure in a dispute or settlement.