How Contractor Estimate Generator Works

This page explains how Contractor Estimate Generator is built and maintained: how the trade templates are put together, how totals are calculated, how PDFs are produced, how we handle your data and how comparison pages are researched. If we change any of this in a way that affects you, we will update this page and its review date.

1. What the tool is designed to do

The tool has one job: turn the details of a job into a clear, itemized estimate or invoice and save it as a PDF. Every feature is judged against that job. Features that would require an account, a server-side database or payment processing are deliberately left out, because they would mean storing your customers' information on our systems.

2. How the trade templates are built

There are eight trade templates: roofing, painting, general construction, plumbing, electrical, HVAC, landscaping and handyman. Each one includes five or six sample line items, written in the units that trade commonly quotes in. Roofing uses squares (100 square feet each), bundles and linear feet; painting uses square feet and linear feet; electrical uses a count of each item.

The sample prices on those line items are illustrative placeholders, not market data. We do not survey contractors or publish average prices for your area, and the numbers in a template should never be sent to a customer as-is. They exist so you can see how a complete line item looks: a description, a quantity, a unit and a unit price. Replace each one with your own costs and margins.

Where a template page offers general guidance, such as what a roofing estimate usually includes, we keep it to widely accepted practice, like listing materials, labor, disposal, permits and warranty terms separately. We avoid presenting cost ranges as facts unless we can cite a public source for them, and we are reviewing older template pages against that rule.

3. How the math works

Each line total is the quantity multiplied by the unit price. The subtotal is the sum of all line totals. If you enter a tax rate, tax is applied to the subtotal and added to produce the grand total. If you enter a deposit percentage, the deposit is calculated on that grand total. A simple worked example:

• 30 squares of shingle tear-off at $75.00 per square = $2,250.00
• 200 linear feet of drip edge at $3.50 per foot = $700.00
• Subtotal = $2,950.00
• Tax at 6% on $2,950.00 = $177.00
• Total = $3,127.00

Those figures are an example of the arithmetic only. The tool does not look up sales tax rates, because rates and the rules on whether labor is taxable differ by state and city. Enter the rate that applies to your job, or leave tax off.

4. How PDFs are produced

PDFs are generated in your browser. Nothing is uploaded to a server to create them. The PDF uses the Inter typeface, which is released under the SIL Open Font License and served from our own site, so names, addresses and phone numbers with parentheses or accented characters render correctly. When a saved estimate is switched to invoice mode, its number is given an INV- prefix so the two documents are easy to tell apart.

5. How your data is handled

Form contents are stored only in your browser's local storage on the device you are using. We do not run user accounts, we do not receive the contents of your estimates, and we cannot recover a draft you have deleted. Clearing your browser data, or using a private window, removes saved drafts. Our privacy policy covers the standard request data our hosting provider processes to deliver the site.

6. How comparison pages are researched

Our comparison pages, such as Joist alternatives and Invoice Simple alternatives, are based on each product's own public website and pricing page. Each page states the date we checked prices, because plans change often. Competitors are named in plain text, and we do not accept payment or affiliate commissions for how a product is described or ranked. If a company tells us a detail is out of date, we check its public page and correct ours.

7. Testing and releases

Before changes go live we create sample estimates and invoices for several trades, check that every line total and the grand total are correct, switch documents between estimate and invoice mode, and download the PDF to confirm that text, logo and totals appear as entered. When a reader reports a bug, we reproduce it, fix it and note the change in the site's update date.

8. Corrections and contact

If you find a calculation error, a broken PDF or an outdated claim, email hello@corneliacove.com or write to Cornelia Cove LLC, 418 Broadway, Ste N, Albany, NY 12207. Include the page address and what you expected to see. We correct confirmed errors promptly. More about who runs the site is on our about page, and the rules for using it are in our terms of service. Nothing on this site is tax, legal or accounting advice.