Which devices are supported?

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

Starlight Tools – Fun Calculators

Q: Do these calculators work offline?

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

Q: 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.

Fun Calculators

Weird but real: playful physics and quirky converters that actually compute. Everything runs in your browser for speed and privacy.

Helium balloons lift calculator preview — kid-friendly interface

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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Earths in the Sun calculator preview — kid-friendly planet size comparison

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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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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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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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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Keyboard Typing Distance

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

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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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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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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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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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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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Frequently asked questions

Do these calculators work offline?

Yes. After the page assets load, the math runs locally in your browser.

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 constants. Some make simplifying assumptions, which are listed on each tool.

What devices are supported?

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