What is Capacity vs usable volume?
Cookers can only be filled two-thirds (or half for dal/rice that foams).
Short answer
For a family of 4, 5 L is the practical everyday size.
Capacity vs usable volume when buying a pressure cooker
Cookers can only be filled two-thirds (or half for dal/rice that foams).
Why it matters: A '3 L' cooker cooks about 1.5 L of dal safely.
Look for: For a family of 4, 5 L is the practical everyday size.
Full Pressure Cooker buying guide