SBL Toolbox · Less busywork. More building.
Tools for Startup Founders
Free, practical tools for founders, small businesses and organisations. Work out costs, plan a project and make documents in a few minutes. No sign-up, and nothing you type leaves your browser.
01 · Plan a build
Thinking about a new tool or app?
Use these before you commission anything. They help you work out whether a problem is worth solving, what it might cost and what to ask for.
Automation Savings Calculator
See what a repetitive manual task costs each year, and how much automating it could save.
App Development Cost Calculator
A rough UK cost and timeline for a tested prototype and a full build, with every assumption shown.
Project Brief Generator
Answer guided questions and download a clear brief to share with your team or a developer.
02 · Run your business
Everyday admin, done quickly
Free Invoice Generator
Make a UK invoice with VAT and bank details, then download it as a PDF. No sign-up.
UK VAT Calculator
Add or remove UK VAT at 20%, 5% or any rate, and see the net, VAT and gross amounts.
03 · How the tools work
Private by design
- Every tool runs in your web browser.
- Nothing you type is sent to us or stored on our servers.
- PDFs are made on your device and saved straight to your downloads.
- Some tools can remember your details in your own browser, only if you tick the box.
- No account, no email address and no trial.
- Built to work with a keyboard and screen reader, in light or dark mode.
04 · Questions
Frequently asked questions
Are the tools really free?
Yes. There is no charge, no sign-up and no limit on how often you use them. They are part of how we help people who are planning or running a business.
Do you see what I type?
No. The tools run entirely in your browser, so your figures, client details and bank details never reach our servers. If you tick a “remember” box, the details are saved in your own browser only, and you can clear them at any time.
Can I use the documents for my business?
Yes. Invoices and briefs you make are yours to use, send and edit. Check that an invoice includes everything your business needs to show, especially if you are VAT registered.
Will you add more tools?
Yes. We are adding more tools over time. If there is a tool you would find useful, tell us.
Can you build a tool like this for my organisation?
Yes. If a task in your organisation is repetitive, slow or error-prone, we can build and test a working prototype with the people who do it. See our builds.
Need a tool that does not exist yet?
We build working prototypes of tools, apps and websites, tested with the people who will use them, so you can decide what to build next with evidence.