Extra Work Calculator — free

Unzip the whole folder and openindex.html. It calculates how extra hours change the return of a fixed-price project and estimates an additional fee. No account/server; inputs are neither saved nor sent.

A result in5minutes

Choose a currency label (no conversion), enter the budget and base hours, add extra hours and optionally a new hourly rate. Use actual base hours for a running project or estimated hours for planning; keep the distinction clear. A blank rate usesbudget/basehours. Review the loss of hourly return and the separate fee scenario. SaveTXT or print for discussion: this is not an invoice, agreement or receipt.

Complete fictional case

12000RUB /12h =1000RUB/h. Six extra hours without extra payment make18h total and666.67RUB/h, a33.33% reduction. Six hours at1000RUB/h cost6000RUB. If both sides agree to include that fee in the budget, the18000RUB /18h scenario returns to1000RUB/h. The calculation does not mean the fee has been paid.

At an800RUB/h custom rate, the proposed fee is4800RUB, the scenario budget16800RUB and hourly return933.33RUB/h. This can be a deliberate decision; the tool shows the arithmetic.

A client message you can adapt

“The request[description] falls outside the current scope. Estimate:[hours], additional fee:[amount], schedule impact:[time]. Before starting, please confirm the new deliverable and price in writing. If we keep the original budget, I suggest removing[scope item] instead.”

Check the original agreement: correcting your own defect is not automatically new chargeable scope. The calculator does not make that decision.

Limits

Gross arithmetic only: no taxes, expenses, platform fees, invoice rounding or exchange rates. Zero budget is allowed; zero base hours is not. Negative values/formulas rejected, decimal commas and grouped spaces accepted. All results are scenarios based on your inputs.

Scope Change Desk adds original scope, a change log, approval evidence and a specific client document. The free tool links directly to its Kornilov Tools product page.

Share card

In “Share the result”, choose “Copy text”, “Download PNG” or “Download HTML”. One “Include figures in all formats” checkbox adds base/extra hours, hourly return after extra work and the proposed fee. All these figures are hidden by default in all three formats. Client and project names are excluded; demos are explicitly marked fictional. Updating the calculation or changing the language turns the checkbox off again. PNG is created locally by the browser and downloaded as an image, not copied to the clipboard. If text copying is unavailable, a selectable text field appears: copy manually using the menu or Ctrl/Cmd+C. Text and HTML include the free Extra Work Calculator URL so the recipient can run their own calculation; the address drawn in the PNG is not clickable. The URL contains only the language and generic UTM tags, without your inputs. Downloads start only when requested; check the file in your downloads. The app never sends anything automatically. The paid next step is available inside the tool.

Support

Kornilov Tools, version 1.1.0. Contact: support on the website. Include the product, version, browser, steps and an anonymized example. Never include passwords, keys or client data.