Phone Charging Speed Calculator
Estimate how long it takes to charge your phone based on battery capacity and charger wattage.
Estimated Charge Time
Charging time depends on battery capacity, charger wattage, and charging efficiency.
Charge Time (hours) = (Battery mAh × Battery Voltage) / (Charger Watts × 1000 × Efficiency)
Simplified: Time ≈ (Battery Wh) / (Charger W × Efficiency)
Common battery sizes (2025):
- Budget phones: 4,000–4,500 mAh
- Mid-range phones: 4,500–5,000 mAh
- Flagships: 4,500–5,500 mAh
- Gaming phones: 5,000–6,000 mAh
Charger wattages:
- USB-A (old): 5W
- iPad/basic USB-C: 10–20W
- iPhone fast charge: 20–30W
- Samsung fast charge: 25–45W
- OnePlus/Oppo: 65–100W
- Xiaomi HyperCharge: 120–200W
Charging efficiency: Typically 75–85% (heat loss, conversion)
Important: Phones charge faster from 0–80% and slow down significantly from 80–100% to protect battery health.