Open Source Freelance Rate Calculator

Work out what to charge from the take-home you want, with tax, costs, unpaid weeks, and non-billable hours all counted — then own the source and change the assumptions.

What you can build

  • A rate calculator for your own currency and tax rules
  • A pricing page calculator for a studio
  • A day-rate versus salary comparison tool
  • An internal margin calculator for an agency

Alternative related foundations

TTProduction Ready

/business / updated Jul 25, 2026

Time Tracker

v1.0.0

A freelance time tracker and weekly timesheet: a running timer, manual entries, per-project rates, billing increments, and a CSV export shaped like invoice lines.

  • Use it today.
  • Create your editable copy.
  • Customize it with AI.
RunnableAgent-readyInstall-readyDeploy-ready
Next.jsReactTypeScript+1
Freelancers billing by the hour, Small agencies reconciling a week before invoicingBest forMITLicense
5 min setupAgent-readyApp Link path

Creates your editable project with setup files and AI-agent instructions.

INProduction Ready

/finance / updated Jul 1, 2026

Invoice & Estimates

v1.0.0

A billing document foundation for estimates, invoices, client approval, payment links, and clean PDF output.

  • Use it today.
  • Create your editable copy.
  • Customize it with AI.
RunnableAgent-readyInstall-readyDeploy-ready
Next.jsReactTypeScript+1
private money workflows, local-first trackingBest forMITLicense
5 min setupAgent-readyApp Link path

Creates your editable project with setup files and AI-agent instructions.

CPProduction Ready

/business / updated Jun 29, 2026

Client Portal

v1.0.0

A polished portal foundation for agencies, consultants, and service businesses that need private client workspaces.

  • Use it today.
  • Create your editable copy.
  • Customize it with AI.
RunnableAgent-readyInstall-readyDeploy-ready
Next.jsReactTypeScript+1
service businesses, foundersBest forMITLicense
5 min setupAgent-readyApp Link path

Creates your editable project with setup files and AI-agent instructions.

Pick a working app. Make it yours.

Try the shared demo, create your editable copy, customize with AI, deploy your App Link, and install your version.

1

Try Demo

Use the original Foundation Base demo.

2

Create My App

Create the editable source package.

3

Customize with AI

Open the folder in Claude Code, Codex, Cursor, or another coding agent.

4

Deploy App Link

Publish your own stable URL.

5

Install Your Version

Add your deployed App Link to your phone or desktop.

Questions

What happens when I click Create My App?

You download an editable source package with setup files and AI-agent instructions. Your copy is separate from the Foundation Base demo.

Does the Foundation Base demo update when I customize my copy?

No. The demo is the original shared version. Install your own deployed App Link when you want your customized app on a device.

Can I use Claude Code, Codex, Cursor, or another agent?

Yes. Foundations are designed to be opened by an AI coding agent after you download and unzip the source package.