RENOBENCH / HOW WE WORK
See the assumptions.
Check the calculation.
RenoBench’s worksheets use transparent arithmetic applied to visitor-entered values. This page explains the shared principles; each tool page documents its own calculation in more detail.
THE SHORT ANSWER
The current tools do not use verified local price feeds. Amounts come from the visitor or a fictional sample. A result is conditional on those inputs and on the scope the visitor has included.
The six pages and their calculation scope.
| Page or tool | Core calculation | Important limit |
|---|---|---|
| Home budget worksheet | Materials + labor + other costs + reserve | Uses the entered amounts; no automatic local pricing |
| Bathroom budget calculator | Tile cartons + materials + labor + other costs + material tax + reserve | One rectangular floor; no automatic wall-tile measurement |
| Flooring calculator | Whole cartons + entered installation and other costs + tax + reserve | Designed for tile sold by the carton |
| DIY vs contractor comparison | Each cash base + its reserve; optional personal time value | No assessment of skill, safety, or contractor quality |
| Contractor quote comparison | Original quote + known excluded costs | Included allowances are not added a second time |
| Project budget builder | Planned categories + reserve; separate actual-cost record | Recorded expenses are not a payment or commitment ledger |
Measurements and whole cartons.
For a rectangle, floor area is length × width. The tile target is area × (1 + the chosen extra-material percentage ÷ 100). Divide the target by carton coverage and round up to a whole carton.
Purchased coverage can exceed the target because packaging is indivisible. The flooring labor calculation uses measured floor area rather than automatically billing for every purchased square foot.
Reserves and taxes.
A reserve is a visitor-selected planning assumption. The tools identify the base to which it applies. The bathroom and flooring tools calculate the selected material tax before applying the reserve; labor tax is not automatically determined.
The general budget worksheet expects tax-inclusive category amounts or taxes entered separately once. No tool decides which tax treatment or permit requirements apply to a property.
Quote comparisons and personal time.
The quote tool adds known excluded costs to each positive quoted total. Unconfirmed or excluded scope statuses do not invent a missing price. Allowance amounts tracked as already included remain inside the original total.
The DIY comparison values your own time under both alternatives using the same personal hourly assumption. It keeps that time value separate from cash spending and does not apply the cash reserve to it.
Rounding, blanks, and incomplete records.
Monetary calculations are rounded to cents as documented by each worksheet. A blank planned cost contributes zero without establishing that the cost is free. A blank actual field in the Project Budget Builder remains unentered unless the visitor confirms final costs and intentionally treats blanks as zero.
The Project Budget Builder compares recorded actual amounts with the entered plan. An unspent difference is provisional while work, purchasing, or invoices are incomplete. It is not a prediction of the remaining project cost.
Data provenance and saving.
Samples are fictional and remain identified after saving. Visitors are expected to replace sample prices and assumptions. RenoBench does not describe these samples as contractor bids or researched averages.
Save uses the browser’s local storage for that worksheet. Saved projects do not automatically synchronize between tools or devices. Export a copy if you need a separate record.
Verification and revisions.
We check calculation cases such as normal totals, blank inputs, extra costs, whole-carton rounding, and saved-data recovery for the affected tools. A successful arithmetic test does not verify user inputs, property conditions, or a WordPress deployment.
The revision date identifies when the page or worksheet was updated. It does not mean every sample price was researched on that date. Read the Editorial Policy for how claims and corrections are handled.
PRACTICAL QUESTIONS
A few useful clarifications.
Does a correct formula guarantee an accurate final project cost?
No. Missing scope, incorrect measurements, unpriced work, or incomplete expense records can make a total unsuitable even when its arithmetic is correct.
Do the tools exchange saved budgets?
No. Current worksheets keep separate saved records in the browser. Transfer relevant amounts manually and avoid recording the same cost twice.
Keep planning with RenoBench.
Prepared by RenoBench. Content revision: October 22, 2026. Examples are illustrative; prices and property-specific requirements must be checked separately.
Planning worksheet. Confirm scope and costs with your contractor.