Spice Conversion Chart
Whole to ground, ground to whole — ground spices are more concentrated, so the amount needs to change too.
Why ground spice replaces less whole spice by volume
Grinding a whole spice breaks it down and exposes far more surface area, releasing its flavor and aroma compounds much more readily — the standard rule of thumb is that 1 teaspoon of ground spice is roughly equivalent to 1 tablespoon of the same spice whole (a 3:1 ratio), similar to the fresh-to-dried herb ratio for the same underlying reason.
Toasting and grinding fresh changes the equation
Pre-ground spices lose potency in storage faster than whole ones, since more surface area means faster flavor loss over time — a whole spice toasted and ground fresh right before use is noticeably more potent than the same weight of a jar of pre-ground spice that's been sitting for months. If a recipe seems under-seasoned compared to what a chart suggests, aging spice is a common, easy-to-overlook reason.
This ratio is a starting point, not a fixed law
Exact potency loss from grinding varies by spice — some (like cinnamon or cumin) hold their strength fairly well either way, while others shift more dramatically. Start with the 3:1 conversion and taste as you go, the same way you would with any substitution that changes concentration rather than swapping in a completely different flavor.