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FINANCE

Mortgage Calculator

Estimate a complete monthly mortgage payment with principal, interest, property tax, insurance, PMI, HOA fees and an amortization schedule.

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Loan Calculator

Calculate monthly payment for any fixed-rate loan.

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BMI Calculator

Calculate Body Mass Index from weight and height.

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Percentage Calculator

Calculate what a percentage of a number is.

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Paint Calculator

Estimate paint needed from wall area and coverage rate.

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Concrete Calculator

Calculate concrete volume for slabs, footings, or circular pads.

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Compound Interest Calculator

Calculate future value with compound interest and monthly contributions.

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ROI Calculator

Calculate return on investment as a percentage.

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Hands-On History

Try an old-school slide rule

Before calculators, this is how multiplication was done.

SIMPLE CALCULATOR TOOLSLOGARITHMIC SLIDE RULE
D
C
Slide-rule reading 2 × 3 = 6

The C-scale 1 is aligned with 2 on the D scale. Read the answer under 3 on the C scale.

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