Convert Calories to Picojoules

Convert Calories (cal) to Picojoules (pJ) instantly and accurately.

Conversion Formula

pJ = cal × 4184000000000

About Calories

A calorie (cal) - the thermochemical calorie - is exactly 4.184 J, defined as the heat to raise 1 g of water by 1°C. Standard since 1954. The calorie is the fundamental unit of heat measurement in thermochemistry: glucose combustion releases 669.9 kcal/mol; water vaporisation requires 539.7 cal/g. Bond dissociation energies in quantum chemistry are often quoted in kcal/mol. Note: the dietary Calorie (capital C) on food labels is 1 kcal = 4,184 J - a factor-of-1,000 difference that causes persistent confusion. 1 cal = 4.184 J = 1.163 × 10⁻³ Wh.

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.

Quick Reference Table

→ Full Energy Converter