Rent true-cost calculator.What that apartment actually costs.

Advertised rent is the base number in the listing. True monthly rent is what the apartment actually costs you per month once you add the recurring add-ons the listing leaves out (parking, pet rent, amenity fee, trash valet, storage), the apartment-side utilities you'll pay every month (electric, gas/water, internet, renter's insurance), the amortized share of one-time non-refundable fees (application, admin, broker, pet fee divided across the lease term), and the opportunity cost of the security deposit and last month's rent sitting in the landlord's escrow at 4–5% APY. On a $1,800 advertised rent the true monthly often runs $2,200–$2,500 once the line items are honest.

Mathematically, yes. A one-month broker fee on a 12-month lease is the equivalent of paying ~$150/mo extra rent every month for a year. Amortizing it across the lease term is the only honest way to compare apartments where one has a broker fee and one doesn't. In New York, the FARE Act took effect June 2024 and shifted broker fees to the party that hired the broker (usually the landlord) for new listings, but many older listings still pass them to the tenant. In most other markets brokers are still tenant-paid, especially in Boston. Whoever pays, it counts as part of the cost of getting into the unit.

Because that money is yours, it's locked up for 12 months, and it's not earning interest you'd otherwise get. A $1,800 deposit sitting in a 4.5% APY high-yield savings account would have earned roughly $81 over a 12-month lease. Some states (Massachusetts, New Jersey, New York, Connecticut, and others) require landlords to pay the tenant interest on the deposit, but the rate is set by statute and typically lags HYSA rates by 2–3 percentage points. The calculator computes the gap between what the deposit could earn and what you actually get back. It's small per month but real, and it compounds across multiple moves.

Anything recurring or upfront that the listing's advertised rent doesn't include. Common ones: parking ($50–$300/mo depending on market), pet rent ($25–$75/mo on top of pet deposit and pet fee), 'amenity fees' (gym/pool access, often $30–$100/mo), trash valet ($20–$35/mo, frequently mandatory), storage closet, package locker, optional renters insurance. One-time fees that get rolled into 'due at signing': application fee, admin fee, move-in fee, pet fee (separate from refundable pet deposit), broker fee. None of these show up in the listed monthly. All of them affect what you actually pay.

Security deposits are refundable by law in every state, less itemized deductions for damage beyond normal wear and tear (the rules vary by state but the principle is universal). Pet fees, by contrast, are typically non-refundable in most states that allow them, and exist alongside a separate refundable pet deposit. Some states (California, for example) treat pet fees as part of the security deposit and apply the same refund rules. Check your state law and the lease language. The calculator treats security deposits and last month's rent as recoverable (with opportunity cost) and treats pet fees, application fees, admin fees, and broker fees as gone the moment you sign.

For comparing apartments, yes. Two listings at the same advertised rent are not the same apartment if one includes heat and one doesn't. In cold-weather cities like Boston, NYC, Chicago, and Minneapolis, a 'gas heat, tenant-paid' studio in an uninsulated walk-up can run $200+/mo in January, while the same advertised rent in a building with heat included is genuinely cheaper. The calculator separates utilities into their own line so you can see exactly what they add. If your lease lists 'water and trash included,' move the $40–$60/mo gas/water field to zero before reading the result.

Things that vary too much by individual circumstance to put in a default: commute cost difference vs. your current apartment (often the biggest hidden number — a $200/mo cheaper rent that adds $300/mo to commute is a net loss), furniture for a first apartment, moving costs, the cost of an unexpected mid-lease move if the landlord doesn't renew, and the cost of breaking the lease if you have to. The numbers the calculator produces are the costs you'll see on the monthly check and at signing. Add the rest before you decide.