Two constraints, one limit
This calculator finds the lower of two maximum prices:
- Cash / Reserves: Your assets are split into two pools. Only accounts with Closing? checked can cover the down payment and closing costs — these are wired at closing. All accounts (weighted by Reserve %) count toward the post-close reserve cushion — most boards require 12 months of carrying costs (maintenance + mortgage), though conservative buildings ask for 24+. Both pools must be sufficient for a deal to work.
- DTI / Income: Your total monthly housing payment (mortgage P+I + maintenance + other debts) must stay within the board's debt-to-income ratio limit on your gross monthly income. Most NYC boards use 25–30% DTI.
Whichever constraint produces the lower max price is your binding limit — you can't spend more than both allow simultaneously.
Closing? checkbox vs. Reserve %
Each account has two independent settings. Closing? — check this for any account you can fully liquidate and wire on closing day (cash, HYSA, brokerage you plan to sell). The full balance then counts toward the down payment and closing costs. Reserve % — the fraction of the balance your board credits toward post-closing reserves. Boards typically credit 100% for cash and HYSA, 70–80% for brokerage (market-volatility haircut), and 0% for retirement accounts (401k, IRA, Roth IRA), which appear on Schedule D of the REBNY financial statement rather than as liquid reserves. You can check Closing? on a brokerage account while setting its Reserve % to 80% — meaning you'd wire the full amount at closing but only 80% counts toward your post-close cushion in the board's eyes.
Mansion tax is tiered
New York's mansion tax starts at 1% on purchases of $1M–$2M and steps up to 3.9% above $25M. The default variable rate (0.5%) covers loan origination fees only, assuming a sub-$1M purchase. If your target price crosses $1M, add 1% to the variable rate. Flip tax (typically 1–3% of sale price) is usually paid by the seller, but some buildings charge the buyer — check the proprietary lease.
This is an estimate — verify everything
Co-op board requirements vary significantly. Your building may have stricter DTI limits, different reserve requirements, or an unusual flip tax structure. Always confirm numbers with a licensed mortgage broker (for rate locks and DTI qualification) and a real estate attorney (for closing costs and the proprietary lease).