EV Battery Capacity Calculator
Convert battery pack voltage and amp-hour capacity into nominal energy capacity in kilowatt-hours.
Educational estimate. Calculator results are for planning and information only, not financial, tax, medical, legal, or engineering advice. Verify important decisions with official sources or a qualified professional.
EV Battery Capacity Calculator
Convert Volts and Amp-Hours to Kilowatt-Hours
📐 Formula & Method
Battery Energy Capacity
This gives nominal energy. Usable energy may be lower because of battery buffers, voltage variation, and operating limits.
📋 How to Use
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1
Enter nominal pack voltage.
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2
Enter amp-hour capacity.
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3
Calculate nominal watt-hours and kilowatt-hours.
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4
Check manufacturer data for usable capacity.
Nominal Versus Usable Battery Capacity
Voltage multiplied by amp-hours gives nominal energy, but an EV battery operates across a voltage range and normally keeps upper and lower buffers. Manufacturer usable capacity is therefore better for range calculations.
🔬 Methodology & Accuracy
Formula: Uses the standard mathematical formula shown in the Formula & Method section above. All computations run client-side in your browser — no data is sent to our servers.
Data sources: Tax bands, contribution limits and regulatory rates are taken from official US (IRS, SSA) and UK (HMRC, gov.uk) publications for the current tax year, and updated when bands change.
Last reviewed: June 2026 · General formula used: Battery Energy Capacity · Accuracy: Results are precise to two decimal places using IEEE-754 double-precision arithmetic. Intended for educational and planning use only.
For informational purposes only. Results are estimates based on the inputs and formulas provided. For financial, tax, medical, or legal decisions, consult a qualified professional. Rates and regulations change — always verify current figures with official sources.