55+
Tools & Calculators
19
Unit Converter Types
8
Interface Languages
0
Signups & Paywalls
See how machines work, in 3D.
Engineering simulators you can drag, spin and scrub: a four-stroke engine, a turbocharger, nine thermodynamic cycles, collisions and lab instruments.
See all simulators
Everything you need to get the number right.
From the first value you type to the link you send, every tool answers instantly and keeps the answer easy to check.
Live results
Type in any field and the answer updates as you type. No submit button, no page reload.
Shareable answers
Converters and the finance calculators keep your inputs in the link. Copy it, and whoever opens it sees the same numbers.
Recent history
Converters remember your last 10 conversions on this device, so you can jump straight back to one.
Popular tools.
Everything in one place.
Every tool, grouped by the kind of question it answers.
Size & Clothing
Transit
You don’t need the formula. Just the numbers.
Start from a real question. Each card opens the tool with these numbers already filled in.
Quick Answers
Popular conversions.
cm to inches 1 inch = 2.54 cm inches to cm 1 inch = 2.54 cm kg to lbs 1 kg = 2.20462 lb lbs to kg 1 lb = 0.453592 kg feet to cm 1 foot = 30.48 cm cm to feet 1 foot = 30.48 cm Celsius to Fahrenheit °F = °C × 9/5 + 32 Fahrenheit to Celsius °C = (°F − 32) × 5/9 km to miles 1 km = 0.621371 miles miles to km 1 mile = 1.609344 km mm to inches 1 inch = 25.4 mm inches to mm 1 inch = 25.4 mm grams to ounces 1 ounce = 28.3495 g ounces to grams 1 ounce = 28.3495 g ml to cups 1 US cup = 236.588 mL cups to ml 1 US cup = 236.588 mL
What people use Siazly for
Everyday questions with a number at the end of them.
“Checking what a home loan really costs before the call with the bank.”
EMI Calculator →“Working out the in-hand salary behind a CTC offer.”
CTC Salary Calculator →“Turning a US recipe’s cups and ounces into grams.”
Cooking & Recipe Converter →“Finding the EU and UK size for shoes bought online.”
Shoe Sizes →“Planning a Delhi Metro trip, with the fare and the interchanges.”
Delhi Metro Planner →“Seeing how a monthly SIP grows over fifteen years.”
SIP Calculator →Why Siazly
No signup. No paywalls. Just fast, accurate tools.
Siazly bundles 55+ converters, calculators, simulators and size charts into one fast, uncluttered site. Every tool runs instantly in your browser — no signup, no paywalls, no interstitials between you and the answer — with real-time results, shareable links, and saved history. A single sponsor banner keeps it free. Pick a category above and start.
The Siazly free pass
₹0 / forever
- All 55+ tools and calculators
- 8 interface languages
- Shareable links to your results
- No signup, no paywall
- Runs right in your browser
Frequently Asked Questions
Quick answers about how Siazly works. Every tool page has its own questions too.
What tools does Siazly include?
Siazly offers 55+ free tools: 19 unit converters (length, weight, temperature, area, volume, speed, time, pressure, energy, power, fuel economy, angle, force, torque, cooking, digital storage, data transfer rate, frequency, typography), 10 engineering simulators and lab tools (IC engine, turbocharger, thermodynamic cycles, refrigeration cycle, heat exchanger, heat transfer, psychrometric chart, collisions and momentum, vernier caliper, resistor color code), 9 finance calculators (loan, hourly to salary, CTC salary, SIP, EMI, GST, compound interest, tip, discount), 6 math calculators (percentage, age, date difference, hours, average, fraction), 5 health calculators (BMI, BMR, ideal weight, running pace, body fat), 5 science calculators (dew point, heat index, wind chill, humidity, altitude), 4 size charts (clothing tops, bottoms, shoes, rings), plus QR Transfer for device-to-device sharing and a Delhi Metro & RRTS journey planner. Every tool is free with no sign-up required.
How accurate are the conversions and calculators?
Unit converters use mathematically exact factors (e.g. 1 inch = 2.54 cm exactly). Science calculators use internationally recognised formulas: NOAA standards for heat index and wind chill, Magnus formula for dew point. Health calculators use the WHO BMI formula and Mifflin-St Jeor equation for BMR. All results are for informational reference.
Can I save and share my conversions?
Yes. Every conversion is encoded in the page URL — copying and sharing the link takes anyone to the same result with your value pre-filled. Siazly also saves your last 10 conversions per tool in browser local storage, shown as quick-access chips below the converter. No account required.
Is Siazly free — any signup, subscription, or fees?
Completely free. There is no sign-up, no subscription, no paywall, and no hidden fees — every converter, calculator, and size chart is available at no cost, forever. A single sponsor banner at the top of the page is what keeps it that way; the tools themselves are never interrupted by ads, popups, or interstitials. Just open the page and start converting.
How do I convert clothing and shoe sizes?
Open Size & Clothing from the top navigation and choose your chart:
- Clothing Tops / Bottoms — US, UK, EU, IT, FR, AU side by side
- Shoe Sizes — US Men/Women, UK, EU, JP, and foot length in cm
- Ring Sizes — US, UK, EU, diameter & circumference in mm
What health and science calculators are available?
Health: BMI, BMR & daily calories, ideal body weight, body fat percentage.
Science: Dew point, heat index, wind chill, relative humidity, altitude & atmospheric pressure.
Math & Finance: Percentage, age calculator, date difference, compound interest, tip, discount.
Does Siazly work on mobile devices?
Yes — Siazly is fully responsive and works on any screen size. All calculations run entirely in your browser with no server requests, so they work even on a slow or intermittent connection. Once the page loads, every conversion is instant.
How do I switch the language?
Click the globe icon in the top navigation to switch language. The Siazly interface is available in 8 languages — English, Spanish, French, German, Portuguese, Hindi, Chinese, and Japanese — and the most-used tools also have fully translated Hindi pages under
/hi/. Your choice persists across all pages in local storage.