Everyday size guide
Seed sizes compared: poppy to chickpea
How does a poppy seed compare with a grain of rice or a chickpea? These six dry seed and grain examples run from 1 mm to 9 mm, measured along the dimensions shown below.
The values are illustrative examples used for these comparisons, not verified averages or fixed sizes for each food. Variety, moisture and individual seeds all make a difference.
Six dry seeds and grains, side by side
| Seed or grain | Dimension compared | Millimetres | Inches |
|---|---|---|---|
| Poppy seed | Length | 1 mm | 0.04 in |
| Chia seed | Length | 2 mm | 0.08 in |
| Sesame seed | Length | 3 mm | 0.12 in |
| Lentil | Diameter across its broad face | 5 mm | 0.20 in |
| Grain of rice | Length | 7 mm | 0.28 in |
| Chickpea | Diameter across the seed | 9 mm | 0.35 in |
Length follows the longest dimension of a seed or grain. Diameter measures across the lentil's broad face or across the chickpea; neither is perfectly round.
All six examples are whole, dry and uncooked. The rice example is a food grain with the husk removed. Cooked rice, soaked chia, cooked chickpeas and split lentils are not represented here.
Rice versus lentil: longer does not mean bigger in every way
In these examples, the rice grain is 1.4 times as long as the lentil is wide.
Left: Grain of rice7 mm length
Right: Lentil5 mm diameter
The rice grain is 7 mm long, while the Lentil is 5 mm across its broad face. Dividing 7 by 5 gives the 1.4× comparison.
That compares two specific dimensions. It does not mean the rice grain is wider, thicker or heavier than the lentil.
Poppy and chia: comparing their lengths
In these examples, the chia seed is twice as long as the poppy seed.
Left: Poppy seed1 mm length
Right: Chia seed2 mm length
The Poppy seed is 1 mm long and the Chia seed is 2 mm long. Both measurements follow the seed's long axis.
The chia example is dry; it does not include the surrounding gel that forms when chia is soaked.
Sesame and chickpea: comparing length with diameter
In these examples, the chickpea is three times as wide as the sesame seed is long.
Left: Sesame seed3 mm length
Right: Chickpea9 mm diameter
The sesame seed is 3 mm long and the Chickpea is 9 mm across.
Each diagram is fitted to its own pair, so compare the marked dimensions within a diagram rather than the apparent picture sizes between diagrams.
You can also compare rice with sesame or poppy with sesame.
Sources and natural variation
The numerical values on this page are defined examples, as explained in our measurement methodology. The sources below provide context about variation; they do not establish these six values as average measurements.
- The Rice Association's guide to rice types explains the differences between long-, medium- and short-grain rice. A single length cannot describe every variety.
- Saskatchewan Pulse Growers' lentil guidance describes different seed-size classes and seed weights. Weight per thousand seeds does not directly establish a lentil's diameter.
Variety, grading, moisture and the individual specimen affect dimensions. Cooking and soaking can change them too, so these dry examples should not be used to estimate cooked sizes.
For a practical comparison, measure several whole, dry seeds of the same type along the same dimension. Record the smallest and largest measurements, rather than treating one seed as a standard.
Looking for a more consistent everyday reference? Explore UK and US coin sizes.
For classroom activities, try estimating and ordering sizes or exploring orders of magnitude.