⭐ Starlight Tools / Fun Calculators

Fun Calculators (18 tools)

Weird but real: playful physics and quirky converters that actually compute, all client-side for privacy. Try our Helium Balloons Calculator, Cloud Storage in Floppy Disks Converter, Love Calculator, or Weight on Every Planet Calculator.

Fun helium balloons calculator – balloons needed to lift a person with 9, 12, and 24 inch sizes

How Many Helium Balloons to Lift You?

Kid-friendly calculator that estimates balloons needed to pretend-lift a weight. 9″/12″/24″ or custom, kg/lb, and safety margin. v1.0

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Fun Earths in the Sun calculator – planet volume comparison dots for a kid friendly view

How Many Earths Fit in the Sun?

Compare planet sizes by volume with a simple dot visual and an optional sphere-packing estimate. Kid-friendly, private. v1.0

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Fun cloud storage to floppy disk converter – floppies, CDs, DVDs, Blu-rays, and VHS equivalents for file size

Cloud Storage in Floppy Disks Converter

Convert KB/MB/GB/TB into floppies, CDs, DVDs, Blu-rays, Zip/Jaz — even VHS tapes. Decimal/binary toggle and kid-friendly visual. v1.0

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Fun tabs capacity calculator – working memory sliders to estimate how many browser tabs your brain handles

How Many Tabs Can Your Brain Handle?

Estimate your comfortable and stretch tab counts using friendly working-memory math, task load, and context. Private, client-side. v1.0.0

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Fun coffee to sleep calculator – caffeine dose, timing, and bedtime delay tradeoff

Coffee-to-Sleep Tradeoff

Estimate bedtime delay and hours of sleep affected from caffeine timing and dose. Adjustable half-life and sensitivity. Private, client-side. v1.0.0

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Fun keyboard typing distance calculator – convert words typed into meters with playful comparisons

Keyboard Typing Distance

Convert words typed into meters and playful equivalents. Adjustable assumptions, private, 100% client-side. v1.0.0

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Fun toilet paper roll length calculator – convert rolls into meters, kilometers, and playful equivalents

Toilet Paper Roll Length Converter

Convert rolls into meters, kilometers, and playful equivalents (Eiffel Towers, football pitches, blue whales). Private, 100% client-side. v1.0.0

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Fun snail mail speed calculator – compare snail travel time to postal delivery time

Snail Mail Speed Calculator

Would a real snail beat the mail? Compare snail travel time (speed + duty cycle) to postal delivery time. 100% client-side.

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Fun weight on every planet calculator – see your weight on Mercury, Moon, Mars, Jupiter and more

How Much Would You Weigh on Every Planet?

Enter your weight (or mass) and see your weight on Mercury, Venus, the Moon, Mars, Jupiter, and more. Real surface gravity. Private, client-side.

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Fun data to paper calculator – convert MB or GB into pages, reams, weight, and stack height

Data → Paper: How Many Pages?

Type a file size (KB/MB/GB), pick encoding and page density, and see pages, reams, paper weight, and stack height. Private, client-side.

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Fun how loud is too loud calculator – convert decibels to intensity, watts per meter squared, and comparisons

How Loud Is Too Loud?

Convert dB to intensity (W/m²) and source watts, estimate energy over time, and see friendly comparisons. Private, client-side.

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Fun love calculator – two name fields with playful compatibility score

Love Calculator

Pop in two names (and optional birthdays) for a playful, privacy-friendly compatibility score—plus friendly notes. v1.0.0

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Fun dog years to human years calculator – breed size selector and age conversion chart

Dog Years to Human Years (Breed-Aware)

Convert dog years to human years with breed/size-aware curves (Classic or DNA). Months input, mini chart, private & client-side. v1.0.0

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Fun nap length calculator – power nap vs full sleep cycle wake up times

Perfect Nap Length Calculator

Power nap or full-cycle? Get wake-up times that dodge grogginess, with latency/chronotype/caffeine tweaks. Private & client-side. v1.0.0

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Fun cell turnover calculator – charting replaced skin, blood, gut, liver, heart cells and more

Cells You’ve Replaced — “Every 7 Years” Myth Calculator

Estimate how much of your skin, blood, gut, fat, bone, liver, heart, and more you’ve likely renewed over time. Friendly, sourced, and 100% client-side. v1.0.0

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Fun email carbon footprint calculator – inbox size CO2 estimate with playful equivalents

Email Carbon Footprint

Estimate your inbox’s CO₂ using simple & advanced modes, with playful equivalents (elephants, kettles). Private, client-side. v1.0.0

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Fun sound travel time calculator – thunder delay and echo distance with temperature adjustment

Sound Travel Time Calculator

How long until thunder reaches you—or your shout echoes back? Enter distance or seconds, adjust temperature, and get time/distance instantly. Private, client-side. v1.0.0

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Fun light travel distance calculator – blink-time distances in meters, km, miles, and space fractions

Light Travel Distance

How far does light go while you blink? Enter microseconds or milliseconds to see distances in meters, km, miles, Earth–Moon fraction, AU fraction, and times around Earth. Private, client-side. v1.0.0

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Frequently asked questions

Do these calculators work offline?

Yes. After assets load, calculations run locally in your browser. Some sharing features may need connectivity.

Do you upload my inputs or results?

No. These tools are client-side; we don’t upload inputs or store personal data.

Are the numbers accurate?

They use real formulas and reasonable constants. Some tools make simplifying assumptions (e.g., standard temperature/pressure, average values). Each tool lists its assumptions.

What devices are supported?

Modern desktop and mobile browsers are supported. Performance depends on your device.

About These Fun Calculators

These fun calculators turn real physics, math, and conversions into playful tools, all running privately in your browser without sign-ups or uploads.

Popular picks include the Helium Balloons Calculator, Cloud Storage in Floppy Disks Converter, Love Calculator, Weight on Every Planet Calculator, and How Loud Is Too Loud?.