How I stopped guessing software prices and built a math model instead

Description and use

The author built Project Estimator, a local tool that consolidates academic cost models into a single equation, enabling accurate hour and price estimates and eliminating under- or overestimation.

Problem

Freelance developers and small agencies often lose money due to inaccurate project estimates, leading to overwork or underpayment.

Outcome

Accurate estimates matched actual billable hours, eliminating overwork and underpayment, and enabling consistent fixed-price proposals.

Workflow

• Define work items and group them into a tree structure.
• Assign base hours for each leaf work item.
• Adjust for deliverable quality, complexity, skill gap, and kept factors using the provided multipliers.
• Add integration hours and optional risk hours based on residual probability and mitigation.
• Calculate nominal hours, total hours, and apply strategy multiplier, discount, and margin to derive final price.
• Export estimate as PDF or JSON, or copy LLM prompt for automation.
• Use the local tool to keep data private and repeatable.

Evidence

After numerous works with different clients that ended up draining a lot of energy because of low estimates, I studied a series of different cost models to better price my works.

Source

The tool is totally free, with no sign-up and no back-end: your data is never recorded anywhere.

Source