Everyday & hobby calculators

7 free tools that don't fit a single trade — pricing, gardening, sewing, and quick household math.

Markup Calculator

Selling price, markup %, and margin % from any two of the three.

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Aquarium Calculator

Tank volume in gallons or liters, plus water weight.

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Dilution Ratio Calculator

Exact concentrate and water amounts for any ratio.

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Plant Spacing Calculator

How many plants fit a garden bed, laid out in rows.

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Circle Skirt Calculator

Waist radius, hem radius, and fabric width for sewing.

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Flag Calculator

A well-proportioned flag size for your flagpole height.

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Kitchen Remodel Cost EstimatorPopular

A rough budget range by kitchen size and finish tier.

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