Clear terms for a useful tool.

The service

BidVariance is a browser-based estimating and decision-support tool created, developed and maintained by Yunus Emre Vurgun as a personal project in Istanbul, Türkiye. See developer and contact details. The app models possible project costs, durations and prices from assumptions supplied by the user. Free calculators use the approximations stated on their pages.

License scope

Licenses are one-time purchases for the scope described on Pricing and in the applicable Gumroad product listing at purchase. Pro covers one user. Business covers up to five internal users within one legal entity. Consultant permits client-facing work for one consultancy, including the stated attribution and handoff features, but does not include white-labeling.

Each tier includes the baseline engine and features advertised for it. Higher tiers add the specified review and client workflows. A license does not provide cloud project storage, shared workspaces, automatic device synchronization, or a hosted calculation API. Do not resell or publicly distribute license keys, bypass license checks, or represent the product as your own. This does not restrict rights that applicable law gives you.

The browser session is valid for up to 30 days before re-verification; that session limit is not an expiry of the one-time license. Reopening the licensed app requires a connection for session verification, and activation/renewal requires Gumroad availability. Access may be refused for an invalid, refunded, disputed or otherwise ineligible purchase.

Purchases, refunds and support

Checkout, receipts and payment handling are provided through Gumroad. Review the final price, applicable taxes, product description and refund terms shown there before purchasing. These terms do not remove cancellation, refund, warranty or other rights that cannot lawfully be excluded. For purchase questions, use your Gumroad receipt or the support contact; never publish your license key.

A one-time purchase is not a subscription. It does not promise uninterrupted availability, a particular future feature, a service-level agreement, or a separately purchased support arrangement. Product functionality may be maintained and updated; statements here do not override specific commitments made at purchase or mandatory consumer rights.

Your data and responsibilities

You retain rights in your project inputs. You are responsible for having permission to use them, choosing reasonable estimates and reviewing outputs. Keep exported backups: browser storage can be cleared, corrupted or removed, and the server does not hold copies of your local projects. Review the privacy notice and storage controls.

Use the service lawfully. Do not attack the service, interfere with other users, automate abusive activation attempts, or misuse another person's data or license.

Model limitations

A probability is conditional on the supplied model; it is not a guarantee of profit, completion, a winning bid or any other result. Simulations have sampling variability. Single-estimate approximations can extend outside the input range. The model does not allocate constrained staff, calculate cash flow, or replace independent contract, accounting, tax, legal or other professional advice. Review the methodology and verify material decisions independently.

Templates and content

You may download and adapt the published project templates for your own estimates and licensed client work. Their values are illustrative, not market benchmarks. Keep BidVariance attribution on generated reports where the selected license requires it. The name, logo, software and site content remain the property of their respective rights holders; no broader resale or white-label right is granted by downloading a free resource.

Availability and liability

To the extent permitted by applicable law, the service is provided as available without a promise that it will be error-free or suitable for every project. You must review assumptions and outputs before relying on them. Nothing in these terms excludes or limits liability, warranties, remedies or statutory rights that cannot lawfully be excluded or limited.

Questions and updates

Contact the developer to raise a service or licensing concern. Applicable law determines any mandatory rights and dispute procedures; these terms do not require arbitration or remove a consumer's right to use a competent court or regulator. Updates will be dated on this page and will not be used to retroactively remove rights already granted by a purchase.