House Flipping Spreadsheet vs Software: What to Track and When to Switch

A house flipping spreadsheet works when it tracks six things: the deal inputs, the rehab estimate by zone, the original plan next to the current forecast and the actual, receipts, contractor bids and milestones. It breaks on a phone during a walk-through, with photos, when the original plan gets overwritten, and when a second house arrives. House flipping software is worth switching to when those breaks start costing money or evenings.

What a good house flipping spreadsheet must track

A fix and flip spreadsheet template that only computes "ARV minus costs" is a calculator, not a tracker. The full list, in the order a deal happens:

The deal inputs

• ARV (after-repair value, what the house should sell for once the work is done) with the three to five comps behind it, and a conservative, base and aggressive figure.
• Purchase price and purchase closing costs.
• Rehab estimate and a contingency on top of it (a reserve for what is hidden; a common rule of thumb is around 10% of the rehab).
• Financing terms: loan-to-cost on the purchase and on the rehab, rate, points, months.
• Holding costs per month (taxes, insurance, utilities, HOA, interest) and the expected months.
• Selling costs as a share of the sale price.
• A target profit, as a figure or a share of ARV.

From these the sheet computes profit, margin (profit ÷ ARV), ROI (profit ÷ cash invested) and the maximum offer. The house flip profit calculator article shows the arithmetic on the example house used across this site (ARV $320,000, repairs $48,000, bought at $200,000, profit $35,000 cash).

The rehab estimate by zone

Roof, exterior, foundation, kitchen, baths, electrical, plumbing, HVAC, interior, windows and doors, garage, yard: one block per zone, with work items, quantities, a unit rate and a line total. A per-square-foot number is a filter, not an estimate. A line you could not price stays empty and marked, and the total is marked incomplete until it is filled.

Original, forecast, actual

Three columns for every budget line, never one:

Variance (forecast) = Current forecast − Original plan
Variance (actual)   = Actual − Original plan
Remaining           = Current forecast − Actual to date

On the example house the rehab line might look like this four months in. It is an example; your lines will differ.

The bath overrun was paid from the contingency, so the total forecast did not move; the reason sits in the last column. A sheet with one budget column would show $52,800 and nothing else, and six months later you would not remember the subfloor.

Receipts, bids and milestones

• An expense ledger: date, vendor, amount, budget line, and the receipt itself.
• Every contractor bid, as received, with its scope, exclusions and the lines matched to your estimate (how to read a contractor bid).
• Milestones with planned and actual dates: closing, rehab start, rehab complete, listed, under contract, sold. A slipped milestone should move the holding-cost forecast, not just a date.

Where a spreadsheet breaks

On a phone, during the walk-through

A walk-through is one-handed work in a dark basement with a flashlight in the other hand. A spreadsheet on a phone wants two thumbs, a visible keyboard and a signal. What actually happens is that notes go into the camera roll and a text to yourself, and the sheet is filled in that evening from memory. The zones you did not photograph are the ones that go missing.

Photos and receipts

A spreadsheet cell holds a number, not the photo of the panel that justified the number or the receipt that proves the expense. The evidence ends up in three apps and a glovebox. At the sale, or when a partner or the accountant asks, the ledger and the receipts have to be reconciled by hand.

The frozen original plan

The single most important discipline in a flip is that the plan you bought on cannot be edited afterwards. In a spreadsheet it can, in one keystroke, by you, with no record. Templates with "Budget" and "Actual" columns typically have the budget get adjusted as the project drifts, which erases the information you most need at the review: what was the plan, what changed, and why.

Several houses

The second house gets a copy of the first file; the third gets a copy of the second, with the fix you made to the first missing. Your rates, your contractors and your past-deal history live in whichever copy you opened last. Insights across deals (where are my estimates off, by category) need the data in one place.

Sharing

The contractor needs the scope without your prices. The partner needs the numbers. The lender needs a package: loan request, sources and uses, ARV evidence, the rehab budget, the timeline. From one spreadsheet that is three evenings of copy-paste and one leak of the ARV to the contractor.

What to look for in house flipping software

The same six things, as a checklist, plus three rules that separate a tool from a toy:

• Deal inputs with scenarios and stress tests: low, base and high ARV; ARV −5%, rehab +20%, three more months.
• Estimate by zone, priced from your own rates, replaceable without starting over.
• A walk-through that works on a phone with photos and notes per zone, offline, synced later.
• Original, forecast and actual stored separately, the original frozen, a reason per change.
• Expenses with receipt capture, bids matched to the estimate, milestones that move the holding forecast.
• Share views per audience: contractor without prices, partner, lender, accountant; links you can revoke.
• Unknown is never $0. An unpriced line should mark the total incomplete, not quietly zero.
• No verdicts. A tool that says "buy" or "don't buy" has hidden its assumptions behind a word. Margin, stress results and data quality in neutral labels are what you need.
• Data export. Your rates, estimates, ledger and past deals in CSV; your records should outlive the subscription.

Also look at what the tool refuses to do. A flipping tool that also wants to be your CRM, your task manager and your contractor marketplace will do each of those averagely and the flip tracking worst of all.

When a spreadsheet is enough

Honestly, often. One house at a time, bought for cash, with a contractor you have worked with before and a partner who trusts your word, does not need software. A careful sheet that counts every cost, keeps a copy of the original plan in a second tab that nobody touches, and sits next to a folder of receipts will carry a flipper through the first deal or two.

The switch point is not a number of houses. It is the moment you cannot answer, in one minute, "what has changed since the plan, and why", or the evening you spend rebuilding a lender package from cells. If you track in a spreadsheet today, at least check it against the list above: does a blank count as zero, can the original plan be edited, and could you hand it to a contractor without the ARV showing.

How Flip Investor OS covers the list

Flip Investor OS is a web app for US house flippers, built for the phone first, in English, Spanish and Russian. Against the checklist:

• Deal analysis with maximum offer, profit, margin, ROI, three ARV scenarios and the stress tests; flip and BRRRR side by side on the same house.
• An estimate by zone priced from your own rates or the starter rates (labelled "Starter estimate — not market data"); an unknown cost is Unpriced, never $0, and a result with unknowns is Incomplete.
• A twelve-zone walk-through on a phone with photos and notes per zone, offline with sync later; the field AI describes what is visible, what is possible and what cannot be verified from a photo, and prices nothing.
• A project with the original plan frozen (the database refuses changes to it), the current forecast and the actual line by line, "what changed and why" per budget line, expenses with receipt scanning that you confirm, milestones, and contractor bids read by AI into lines you confirm and compared with the estimate.
• Read-only share links and PDFs for a contractor (scope, no prices), a partner, a lender and an accountant; links you can revoke.
• History: past deals, estimate vs bid vs actual by work category, personal accuracy; insights are facts from your own projects, never a verdict. A deal score describes margin of safety and data quality with neutral labels; the app never says buy or don't buy.

The free account has eight free calculators (maximum offer, ARV from comps, flip profit, rehab cost by size, holding costs, hard money, BRRRR, rental quick check) and demo data to look around, with no card. Open the free calculators and run your current spreadsheet's house through them; if the numbers agree, your sheet is sound, and if they do not, you have found the line to fix. Tracking live properties and projects is on the paid plans (Starter and Pro, with a 14-day trial).

Costs and the right tool vary by market and by how many houses you run; the example figures here are an example. Whatever you use, the discipline is the same: every cost on its own line, the original plan frozen, unknowns kept unknown, and the decision made by you.