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Speedometer Gear Calculator
Number of teeth for the speedometer driven gear after a tire or axle ratio change.
Engineering Calculators
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Free engineering calculators for everyday questions, from quick checks to detailed breakdowns.
Engineering tools (37)
- Tested
Spring Constant Calculator
Hooke's law spring constant and stored energy.
Engineering Calculators
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Strain Calculator
Engineering strain from change in length.
Engineering Calculators
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Stress Calculator
Normal or shear stress from force and area.
Engineering Calculators
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Thread Pitch Calculator
Convert between threads per inch and pitch in millimeters.
Engineering Calculators
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Three-Phase Power Calculator
Real, apparent and reactive power of a balanced three-phase load.
Engineering Calculators
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Transformer Turns Ratio Calculator
Secondary voltage from primary voltage and turns.
Engineering Calculators
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Transmission Gear Ratio Calculator
Vehicle speed from engine rpm, gear ratio, final drive and tire size.
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Voltage Divider Calculator
Output voltage of a two-resistor divider.
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Watt-Hours Calculator
Energy in watt-hours from power and time, or from amp-hours and voltage.
Engineering Calculators
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Wattage Calculator
Solve power, voltage or current for a DC or resistive load.
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Window Air Conditioner Size Calculator
Cooling capacity (BTU/h) for a room, from the ENERGY STAR room air conditioner sizing chart.
Engineering Calculators
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All engineering calculators by topic (37)
Automotive
Circuits
Components
Electrical
Fasteners
General
Hydraulics
Mechanical
Rotation
Shipping
Vehicles
About engineering calculators
Engineering Calculators help you turn a question into a clear, checkable answer. Each tool lists its inputs, shows the formula it relies on and explains how to read the result.
Browse by topic using the filters, or search for a specific tool. Tools that are still being built are clearly marked as previews and are not presented as finished calculators.
Frequently asked questions
Are the engineering calculators calculators free?
Yes. Every calculator on Calculator Atlas is free to use and requires no sign-up.
How are results verified?
A calculator is only published after its formula has been implemented, tested against independently computed reference values. It is an automated check, not a professional review.