About BuildByJai
My name is Jawad. I build interactive tools — calculators, quote estimators, assessments, diagnostics and lead magnets — for agencies and service businesses across the UK.
BuildByJai started as a library of free tools I built to solve real practical problems: accurate VAT calculators, concrete estimators, income tax tools. Things people actually search for and use every day.
Over time I noticed that the same logic that makes a free tool useful — a structured question flow, an instant result, a specific job done well — is exactly what a business needs to turn a website visitor into a genuine enquiry. A quote estimator that captures contact details. An eligibility checker that qualifies a lead before a call. An assessment that gives a visitor a reason to stay on the page.
That's the commercial side of what I do. I build custom versions of those tools for agencies and service businesses: branded to their identity, connected to their enquiry process, and focused on a specific job the website needs to do.
What I build
Quote and cost estimators
Give visitors an indicative price based on what they select, and capture contact details at the end.
Eligibility and suitability checkers
Help visitors understand whether a service, scheme or product is right for them before they enquire.
Assessments and diagnostics
Walk visitors through a structured set of questions and give them a clear, useful result.
Recommendation tools
Guide visitors to the right product, service or next step based on their situation.
Interactive lead magnets
Tools designed to capture better-qualified enquiries by giving visitors something genuinely useful first.
Branded versions of existing free tools
Adapt an existing calculator or utility with your branding, service area and lead-capture flow.
How I approach the work
I prefer focused tools over bloated software. A tool that does one job well — and does it reliably — is more useful than a platform with twenty features that visitors ignore.
Each build starts with the job the visitor needs to do. What are they trying to calculate, estimate, check or understand? What would make them stay on the page rather than leave? What information would be worth giving up their contact details for?
The free tool library exists for the same reason. Every tool on the site does a specific, practical job. That's the standard I apply to custom builds too.
Clear logic
Calculations are transparent, deterministic and auditable. No black boxes.
Clean interfaces
Mobile-first designs that remove friction from the visitor's path.
Focused scope
Each tool does one job without bloat. Better to do one thing well.
Who this is designed for
Service businesses that get the same questions from prospects repeatedly — about price, suitability or how the service works — and want a better way to answer them at scale.
Agencies that want to offer custom interactive tools to clients as part of websites, campaigns or lead-generation work, without building each tool internally.
Anyone who wants to use one of the free tools without creating an account, or who wants to understand what's possible before committing to anything.
Get in touch
If you have a question, a project brief, or just want to understand what's possible, the quickest way is to use the enquiry form or email directly.