Approved is not the same as affordable
Every big purchase has a moment where somebody quotes you a figure. A lender’s pre-approval letter. A dealer’s monthly payment. A venue’s package price. A financial aid award. That figure is real, and it answers a real question — it is just not answering yours.
The question a lender asks is: how much can this household repay without defaulting often enough to cost us money? It is measured on gross income, before the tax and retirement contributions you never see. It counts the debts on your credit report and nothing else — not childcare, not the tuition you pay in cash, not the parent you help every month. And it stops at the loan payment, which on anything you own rather than merely borrow against is only part of what holding it costs.
The result is systematic rather than occasional: the approval number is larger than the affordable number, usually by a wide margin, and there is nobody in the transaction whose job it is to tell you so. The agent, the dealer, the loan officer, the venue coordinator and the admissions office are all paid more when the number is bigger. That is not a conspiracy — it is an absence. This workbook is the missing neutral party.
Three ceilings, and the smallest one is your answer
Your real affordability ceiling is not one number, it is the lowest of three. This workbook computes all three, takes the minimum, and — most usefully — tells you which one is binding.
1. The debt-to-income ceiling
Your gross monthly income times the debt-to-income cap, minus every monthly payment you already owe, is the room left for a new payment. The workbook turns that payment back into a price — through the loan’s own payment factor, with ownership costs riding along — and that is the ceiling your income supports.
2. The cash-and-reserves ceiling
Liquid savings, less anything already earmarked, less an emergency reserve of several months of essential spending, divided by the down payment plus the upfront costs. Most online calculators skip this one, because from a lender’s point of view your savings have done their job the moment the transaction closes. Arriving at closing with a payment you can make and nothing behind it is not affording something — it is postponing the moment you find out you couldn’t.
3. The comfort ceiling
A multiple of your annual gross income — or of a benchmark you choose, like your home’s value for a renovation or an expected starting salary for tuition. The blunt sanity check the other two miss, because payment math can be satisfied by stretching a loan out long enough and cash math by a generous gift. Neither notices that the purchase is simply too large for the income underneath it.
The binding constraint is the line that changes what you do
Knowing your ceiling is useful. Knowing which of the three is holding it there is what turns a vague plan into a specific one, because the levers that move one ceiling do nothing at all to the other two.
If cash binds, saving longer is your lever and a better rate is worth almost nothing. If debt-to-income binds, another six months of saving buys you nothing at all — the pre-filled example returns the identical ceiling at six months and at twelve — and the lever you want is the debt column instead. No lender’s calculator will ever show you this, because a lender only computes one of the three.
Six purchase types, each with its own rules
A house and a car are not the same problem, and a wedding is a different problem again. The Purchase Rules tab carries a curated row for each — home, car or truck, wedding, tuition (per year), home renovation, and a custom row for anything else — holding its down payment, planning rate, term, annual ownership cost, upfront costs, debt-to-income caps, comfort multiple and emergency reserve months. Pick a type on the setup tab and every one of those figures flows into the model through a lookup; each row also carries a written note on where its convention comes from, and every cell is editable.
It also models the thing most calculators quietly get wrong: buying a home replaces the rent you pay today in your debt stack. Buying a car does not — you keep paying for housing on top. That one flag moves the answer more than almost anything else on the tab.
What each price actually costs you
The Price Ladder prices the same purchase at twelve points around your ceiling. Every rung shows the loan payment, the ownership costs, the all-in monthly figure, what share of your take-home pay that is, your debt-to-income ratio afterwards, the cash you would have left, and how many months of essential spending that cash would cover — with a Comfortable, Stretch or Over verdict on each.
The rows above your ceiling are shown deliberately. A decision to stretch should be made in front of the number it costs, not away from it.
What actually moves the ceiling
The Wait & Save tab runs your position today plus seven moves against it — save six more months, save twelve, clear one card, clear the auto loan too, take a better rate, stretch the term, put more down — and re-solves all three constraints from scratch for every one of them. Each row reports what the move is worth in purchase price and which constraint is still binding afterwards.
Two of those rows surprise almost everyone. Saving longer stops helping the moment debt-to-income becomes the limit. And clearing a large balance out of your own savings can lower your ceiling, because the cash you spent doing it was the cash that had to reach the closing table — so the workbook charges the balance as well as crediting the freed payment, which is what keeps a payoff row from looking like free money it is not.
Own it, don’t rent it
Nearly every affordability calculator online belongs to somebody who is paid more when the number is bigger. It stops at the payment, it wants your email, and it is not neutral about the answer.
This is the middle ground between that and building the model yourself in a blank spreadsheet: a structured file you own outright, that shows its work and takes nothing from you. Your figures go to no lender, no lead form, and not to us — the file is yours, and it works offline. No monthly fee, no lock-in, no lead form — and it is still there next year, with your numbers in it, for the next big purchase and the one after that.
What one payment is really costing you
The Raising Your Ceiling guide prices every debt in the example household individually, and the result is the most useful thing in the bundle: $36,000 of balances is suppressing $92,372 of purchase price, because the ceiling never asks what you owe — only what you pay each month. A $126 card minimum alone is holding down $15,707. The same guide closes with six signs a number is too big whatever the model says.
Try the free version first
Want to see the shape of the answer before you buy? The free Big-Purchase Affordability Estimator runs the first of the three tests — the debt-to-income ceiling, for a home purchase — in one tab, pre-filled with a worked example. No email, no signup. The full workbook adds the other two ceilings, the binding constraint, the six purchase types, the price ladder and the wait-and-save scenarios.
Works in Excel, Google Sheets and LibreOffice
Download the .xlsx and open it in Excel or LibreOffice Calc. Prefer Google Sheets? The bundle includes a clickable link to a ready-made native Google Sheet — click Make a copy and it lands in your Drive fully set up, with every dropdown, format and live formula already working. No import, no rebuilt formulas.
The fine print
This is a financial planning model, not licensed financial, tax, lending or legal advice, and nothing it produces is an offer of credit or a prediction that you will be approved for anything. Every figure that ships in the file is an illustrative example for a household that does not exist, and every rule on the Purchase Rules tab is a planning convention you can edit rather than a quote, a law or a statistic. Debt-to-income limits vary by lender, loan program and credit profile; ownership costs vary by market and by what you buy; rates move constantly. Confirm what matters with your lender and a professional who knows your full situation.
A ceiling cannot price a school district, a job you would take a pay cut for, or a wedding your family will remember for thirty years. What it can do is tell you the shape of the space those judgments have to fit inside — which is exactly the thing nobody else in the transaction is going to tell you.
