How I Built a High-Performance, Treadmill Calorie Core Suite (Vanilla JS)

Farhan Adil — Thu, 09 Jul 2026 10:23:15 +0000

Frustrated by slow, bloated online calculators covered in dozens of flashing display ads, I decided to build a high-performance alternative from scratch: TreadmillCalc

To keep the platform instantly interactive, I intentionally bypassed heavy frameworks and coded the calculation suite entirely in Vanilla JavaScript.

The engine uses the exact American College of Sports Medicine (ACSM) metabolic equations to compute raw, scientifically backed calorie expenditure based on weight, speed, duration, and gradient incline.

Here is the core logic handling the real-time calculations:


javascript
function calculateTreadmillKcal(weightKg, speedMph, inclinePercent, durationMins) {
    const speedMpm = speedMph * 26.8; 
    const grade = inclinePercent / 100; 
    let vo2 = 0;

    if (speedMph <= 3.7) {
        vo2 = (0.1 * speedMpm) + (1.8 * speedMpm * grade) + 3.5; // Walking
    } else {
        vo2 = (0.2 * speedMpm) + (0.9 * speedMpm * grade) + 3.5; // Running
    }

    const kcalPerMin = (vo2 * weightKg) / 200;
    return parseFloat((kcalPerMin * durationMins).toFixed(1));
}

How I Built a Free Password Strength Checker (No Passwords Ever Leave Your Browser)

Farhan Adil — Tue, 20 Jan 2026 14:33:00 +0000

Weak passwords are still one of the biggest security risks.
As a small experiment, I built a free password strength checker that runs entirely in the browser.

What makes it different:

No passwords are stored or sent to any server

Uses entropy-based checks, not simple rules

Works offline once loaded

Mobile and desktop friendly

I noticed most tools either feel outdated or push signups.
My goal was to keep it simple, fast, and privacy-first.

👉 Try the tool here:
Password Giant Password Strength Checker

I am also adding a password generator with customizable length and character sets.

If you are a developer or student, feedback is welcome.
Happy to improve it further.

DEV Community: Farhan Adil

How I Built a High-Performance, Treadmill Calorie Core Suite (Vanilla JS)

How I Built a Free Password Strength Checker (No Passwords Ever Leave Your Browser)