Convert Picojoules to Watt-Hours
Convert Picojoules (pJ) to Watt-Hours (Wh) instantly and accurately.
Conversion Formula
Wh = pJ × 2.777777778e-16
About Picojoules
A picojoule (pJ) is 10⁻¹² J - the scale of laser pulses in scientific instruments and chip-level capacitor storage. A 1 pF capacitor charged to 1 V stores exactly 0.5 pJ. Laser pulse energies in OCT and ultrafast spectroscopy are typically 1-1,000 pJ. Single-photon SNSPD detector dead-time dissipates 1-100 pJ per event. Phase-change memory cells (PCM, ReRAM) switch at 10-100 pJ per state transition, setting a lower bound on non-volatile memory energy efficiency. 1 pJ = 10⁻¹² J = 6.242 MeV.
About Watt-Hours
A watt-hour (Wh) is the energy delivered by 1 watt for one hour - exactly 3,600 J. It is the practical unit for small-scale electrical energy: a 10,000 mAh 5 V power bank stores 50 Wh; a laptop battery holds 50-90 Wh; a smartphone battery holds 10-15 Wh; an AA alkaline cell stores ~3 Wh. LED lamps labelled 9 W save 51 Wh/h over a 60 W incandescent. IATA dangerous-goods rules use Wh as the threshold for lithium batteries in aircraft: cells >20 Wh and batteries >100 Wh need special approval. 1 Wh = 3,600 J = 3.412 BTU.
Quick Reference Table
| Picojoules (pJ) | Watt-Hours (Wh) |
|---|---|
| 1 pJ | 2.778 × 10-16 Wh |
| 2 pJ | 5.556 × 10-16 Wh |
| 5 pJ | 1.389 × 10-15 Wh |
| 10 pJ | 2.778 × 10-15 Wh |
| 25 pJ | 6.944 × 10-15 Wh |
| 50 pJ | 1.389 × 10-14 Wh |
| 100 pJ | 2.778 × 10-14 Wh |