How do you convert amp hours to kWh?

Multiply amp hours by battery voltage, then divide by 1,000. kWh = (Ah × V) ÷ 1,000. A 100Ah battery at 12V holds 1.2 kWh. The same 100Ah at 48V holds 4.8 kWh — four times the energy at four times the voltage.

What voltage should I use for my battery bank?

12V systems are common for small RV and boat setups, 24V for mid-size solar installations, and 48V for whole-home battery systems and larger off-grid arrays. Higher voltage reduces wire losses and allows smaller wire gauges for the same power — 48V systems are standard for home battery products like Powerwall and Franklin.

How do I convert kWh back to amp hours?

Divide kWh by the system voltage: Ah = (kWh × 1000) ÷ voltage. For example, 10 kWh at 48V equals 208 Ah. This is the same formula reversed — the calculator supports bidirectional conversion.

Quick answer: A 100 Ah battery at 12V holds 1.2 kWh; at 48V, the same 100 Ah holds 4.8 kWh — four times the energy because the voltage is four times higher.

Quick Tools

Amp Hours to kWh Calculator

Convert amp hours to kilowatt hours (and back) at any battery voltage — 12V, 24V, or 48V. Instant bidirectional conversion.

Amp-Hours / kWh Converter

Conversion direction

Amp-hours (Ah)

Battery voltage

Kilowatt-hours

1.2 kWh

Also: 1.2 kWh = 100.0 Ah at 12V

How we calculate Ah to kWh

Amp hours measure charge without accounting for voltage. Kilowatt hours measure actual energy — charge multiplied by voltage. The conversion scales linearly with system voltage.

kWh = Ah × Volts ÷ 1,000

To convert back, divide kWh by voltage and multiply by 1,000: Ah = (kWh × 1,000) ÷ V.

Frequently Asked Questions

How do you convert amp hours to kWh?: Multiply amp hours by battery voltage, then divide by 1,000. kWh = (Ah × V) ÷ 1,000. A 100Ah battery at 12V holds 1.2 kWh. The same 100Ah at 48V holds 4.8 kWh — four times the energy at four times the voltage.
What voltage should I use for my battery bank?: 12V systems are common for small RV and boat setups, 24V for mid-size solar installations, and 48V for whole-home battery systems and larger off-grid arrays. Higher voltage reduces wire losses and allows smaller wire gauges for the same power — 48V systems are standard for home battery products like Powerwall and Franklin.
How do I convert kWh back to amp hours?: Divide kWh by the system voltage: Ah = (kWh × 1000) ÷ voltage. For example, 10 kWh at 48V equals 208 Ah. This is the same formula reversed — the calculator supports bidirectional conversion.

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Amp Hours to kWh Calculator

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Reviewed April 2026

Methodology and source note

PowerSizing calculators use shared formulas, documented assumptions, and current planning inputs that are summarized on the methodology page. Use these tools for first-pass planning, comparison, and sanity checks, then confirm local code, pricing, utility tariff, and installer specifics before you buy equipment.