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Battery Runtime Calculator
Runtime of a battery under a constant load.
Engineering Calculators
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Free engineering calculators for everyday questions, from quick checks to detailed breakdowns.
Engineering tools (37)
- Tested
CFM Calculator
Airflow in cubic feet per minute from duct velocity or air changes.
Engineering Calculators
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Current Divider Calculator
Current through each of two parallel resistors.
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Dimensional Weight Calculator
Dimensional (volumetric) weight using a carrier divisor you enter.
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Efficiency Calculator
Efficiency as output divided by input.
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Engine Torque Calculator
Convert between engine power and torque at a given rpm.
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Friction Loss Calculator
Pipe friction head loss with the Hazen–Williams equation.
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Gallons per Minute Calculator
Flow in gallons per minute from pipe size and velocity, or volume and time.
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Gear Ratio Calculator
Ratios for gear trains.
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Gear Speed Calculator
Output speed and ratio of a gear pair.
Engineering Calculators
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Inductive Reactance Calculator
Reactance of an inductor at a frequency.
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LC Resonant Frequency Calculator
Resonant frequency of an LC circuit.
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.