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Pico- (Prefix) — Definition, Formula & Examples

Pico- is a metric prefix that means one trillionth, or 10−1210^{-12}. It is placed before a unit of measurement to indicate an extremely small quantity, such as a picosecond (one trillionth of a second).

The SI prefix pico- (symbol: p) denotes a factor of 10−1210^{-12}, equal to 11,000,000,000,000\frac{1}{1{,}000{,}000{,}000{,}000}. When attached to a base unit, it multiplies that unit by this factor.

Key Formula

1 p(unit)=10−12 (unit)1 \text{ p(unit)} = 10^{-12} \text{ (unit)}
Where:
  • p\text{p} = The pico- prefix symbol
  • 10−1210^{-12} = One trillionth, the multiplication factor

How It Works

To use pico-, attach it to the front of any metric unit. For example, 1 picometer (pm) equals 10−1210^{-12} meters. To convert from a pico- unit to the base unit, multiply the value by 10−1210^{-12}. To convert from the base unit to a pico- unit, multiply by 101210^{12}. Pico- sits between femto- (10−1510^{-15}) and nano- (10−910^{-9}) on the scale of SI prefixes.

Worked Example

Problem: A capacitor has a capacitance of 47 picofarads (pF). Express this value in farads (F).
Step 1: Recall that pico- means 10−1210^{-12}, so 1 pF = 10−1210^{-12} F.
1 pF=10−12 F1 \text{ pF} = 10^{-12} \text{ F}
Step 2: Multiply 47 by the conversion factor.
47 pF=47×10−12 F=4.7×10−11 F47 \text{ pF} = 47 \times 10^{-12} \text{ F} = 4.7 \times 10^{-11} \text{ F}
Answer: 47 pF=4.7×10−11 F47 \text{ pF} = 4.7 \times 10^{-11} \text{ F}

Why It Matters

Pico- appears frequently in electronics (picofarads for capacitors) and physics (picoseconds for ultra-fast laser pulses). Understanding SI prefixes like pico- is essential for reading scientific notation and converting between measurement scales in science courses.

Common Mistakes

Mistake: Confusing pico- (10−1210^{-12}) with nano- (10−910^{-9}).
Correction: Pico- is 1,000 times smaller than nano-. Remember the order: milli, micro, nano, pico — each step is 1,000 times smaller.