About CalcTechLab
Free UK calculators built by a British engineer and AI scientist — as a passion project
Arsalan Rahi
AI Scientist & Data Analyst
Electronics & Embedded Systems Engineer
United Kingdom
Pakistani-born, British
The Story Behind CalcTechLab
Hi — I am Arsalan Rahi, a Pakistani-born British AI scientist, data analyst, electronics engineer and Python developer. CalcTechLab is my passion project — something I build and maintain in my free time because I genuinely believe useful tools should be free and accessible to everyone.
As someone who works daily with data, machine learning and engineering systems, I regularly needed quick and reliable calculations — mortgage repayments, salary breakdowns, BMI checks, compound interest. Every site I found was either plastered with intrusive ads, required a signup just to see results, or was built entirely for US users with dollars and American tax rates that meant nothing to anyone in the UK.
So I started spending my evenings and weekends building CalcTechLab — a collection of free tools built specifically for UK users. No signup. No paywalls. No nonsense. Just free tools that actually work.
What started as a handful of calculators has grown to 39+ free tools covering finance, health, maths, conversions and more — and I keep adding new ones whenever I get the time.
Academic Background
MPhil — Artificial Intelligence & Machine Learning
University of Hertfordshire
Advanced research in machine learning with a focus on real-world engineering applications. Research includes highway traffic flow prediction using deep learning architectures — conducted alongside professional work in my spare time.
MSc — Embedded Intelligent Systems
University of Hertfordshire
Specialist study in embedded systems design, intelligent control systems, real-time computing and microcontroller-based architectures. Developed a strong foundation in building intelligent hardware and software systems.
BEng — Electronics Engineering
Ghulam Ishaq Khan Institute of Engineering Sciences and Technology (GIKI) · Batch 20 (2014)
Foundation in electronics engineering, circuit design, signal processing, digital systems and engineering mathematics at one of Pakistan's most prestigious engineering institutions. The first step into the world of engineering that led to everything that followed.
Technical Expertise
Artificial Intelligence
Deep learning, neural networks, predictive modelling and AI-driven automation systems
AI Automation
Designing and deploying intelligent automation pipelines using machine learning and Python
Python Development
Expert-level Python for data science, machine learning, web development, scripting and automation
Data Analysis
Advanced data analysis and visualisation using Power BI, Tableau and Python libraries
Embedded Systems & Microcontrollers
Programming and deploying microcontroller-based systems including ARM, AVR and FPGA platforms
Internet of Things
Designing internet-connected embedded systems and IoT solutions with remote monitoring and control capabilities
Technical Support
Extensive experience delivering technical support and resolving complex engineering and software problems
Full Stack Development
End-to-end web development using Django, REST APIs, JavaScript and cloud deployment
Technologies & Tools
What CalcTechLab Offers
39+ free tools built specifically for UK users — and growing
UK Finance Tools
Mortgage calculator, salary and tax calculator, stamp duty, compound interest and our Personal Finance Compiler with Financial Health Score.
Health Calculators
BMI, BMR, calorie calculator, pregnancy calculator — all using UK health guidelines and ranges.
Maths Tools
Percentage calculator, scientific calculator, abacus, GPA calculator and more.
Conversion Tools
Length converter, temperature converter, ring size converter and more.
Utility Tools
Invoice generator, QR code generator, password generator, word counter, typing test and more.
Productivity Tools
Exam timer, date calculator, age calculator, random name picker and more.
Our Principles
Accuracy
Every formula verified against official UK sources — HMRC, NHS, Bank of England.
Free Forever
Every tool is completely free. No hidden costs, no subscriptions, no signup required.
Privacy First
Your calculation data never leaves your browser. We do not store what you calculate.
UK Focused
Built for UK users with correct tax rates, currency, regulations and guidelines.
Get In Touch
Have a suggestion for a new tool? Want to discuss a data or AI project? Found a bug? Or just want to say hello? I read every message personally.
Contact Form
Send a MessageTry CalcTechLab Today
39+ free UK calculators — no signup, no paywalls, no nonsense.