Battery mAh to Watt-Hours (Wh) & Runtime Calculator
Convert battery capacity from milliamp-hours (mAh) to Watt-hours (Wh) and check TSA 100Wh airline carry-on compliance.
Reviewed by: Alexei Volkov • Principal Systems & Cloud Infrastructure Architect
Methodology: Verified Formula
Presets:
Energy Capacity in Watt-Hours
74.0 Wh
Estimated Runtime at 15W
4.2 Hours
Flight / TSA Status
TSA Carry-On Approved (<=100Wh)
Accounts for 85% DC-DC conversion efficiency.
Scenario Comparison & Benchmark Table (mAh to Wh Converter)
Compare how scaling Battery Capacity (mAh) affects your output (click any row to load those values into the calculator above):
| Battery Capacity (mAh) | Energy Capacity in Watt-Hours | Estimated Runtime at 15W | Flight / TSA Status |
|---|---|---|---|
| 10,000 | 37.0 Wh | 2.1 Hours | TSA Carry-On Approved (<=100Wh) |
| 15,000 | 55.5 Wh | 3.1 Hours | TSA Carry-On Approved (<=100Wh) |
| 20,000 (Baseline) | 74.0 Wh | 4.2 Hours | TSA Carry-On Approved (<=100Wh) |
| 25,000 | 92.5 Wh | 5.2 Hours | TSA Carry-On Approved (<=100Wh) |
| 30,000 | 111.0 Wh | 6.3 Hours | Airline Approval Needed (100-160Wh) |
| 40,000 | 148.0 Wh | 8.4 Hours | Airline Approval Needed (100-160Wh) |
Mathematical Formula & Step-by-Step Guide
Primary mathematical equation used by this model:
Watt-Hours (Wh) = (mAh × Voltage) / 1,000; Usable Runtime = (Wh × 0.85) / Load Watts
- Configure your primary input (Battery Capacity (mAh), baseline set to 20,000) using either the direct numeric box or synchronized range slider.
- Adjust the remaining parameters (Nominal Voltage (V - Li-Ion = 3.7V, LiFePO4 = 12.8V), Device Power Draw (Watts)) to mirror your exact scenario.
- Examine the primary output alongside the secondary breakdown metrics and the 6-tier benchmark comparison table below.
Primary Standards & References: IETF RFC 8259 (JSON), RFC 4648 (Base64), RFC 9562 (UUIDv4), IEEE 802.3 / CIDR RFC 4632, POSIX.1-2017 File Permissions & Official 2026 LLM Tokenizer Pricing
All encoding, formatting, and cryptographic operations execute 100% locally in your browser via Web Crypto & V8 APIs—zero payload data leaves your device.
All encoding, formatting, and cryptographic operations execute 100% locally in your browser via Web Crypto & V8 APIs—zero payload data leaves your device.
Frequently Asked Questions — mAh to Wh Converter
What mathematical formula does the Battery mAh to Watt-Hours (Wh) & Runtime Calculator use?
This calculator implements the verified relationship: Watt-Hours (Wh) = (mAh × Voltage) / 1,000; Usable Runtime = (Wh × 0.85) / Load Watts. Each variable (Battery Capacity (mAh), Nominal Voltage (V - Li-Ion = 3.7V, LiFePO4 = 12.8V), Device Power Draw (Watts)) is evaluated in real time using double-precision floating-point arithmetic so there is zero rounding drift across multi-step scenarios.
How does changing Battery Capacity (mAh) impact the final result?
Battery Capacity (mAh) acts as the primary driver in this model (default baseline: 20,000). Use the Reference Benchmark Table on this page to compare how scaling Battery Capacity (mAh) from conservative to aggressive levels changes both the primary outcome and secondary ratios.
What standards and sources back this mAh to Wh Converter methodology?
Our model is audited by Alexei Volkov • Principal Systems & Cloud Infrastructure Architect and calibrated against IETF RFC 8259 (JSON), RFC 4648 (Base64), RFC 9562 (UUIDv4), IEEE 802.3 / CIDR RFC 4632, POSIX.1-2017 File Permissions & Official 2026 LLM Tokenizer Pricing. Note: All encoding, formatting, and cryptographic operations execute 100% locally in your browser via Web Crypto & V8 APIs—zero payload data leaves your device.