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Mass

Just how heavy is 25 grams?

In your hand

25 g

Scale
25 grams

The quantity is exact as entered.

0.025 kgMass in kilograms
0 kg
Sand dollar

A sand dollar is a flat, burrowing sea urchin with a rigid, disc-shaped skeleton, often found in sandy coastal waters.

0.025 kgDefined live mass in kilograms
0 kg

Bar length measures mass, not physical size. Both bars start at zero kilograms (kg). Pictures identify the objects only.

A little perspective

25 grams is approximately equal to the live mass of a sand dollar.

Measurements, assumptions & sources +

25 grams

Mass: 25 g; definition.

The quantity is exact as entered. Comparisons use the clearly stated specimen, model or nominal measurement.

NIST — SI conversion factors

Sand dollar

Defined live mass: 25 g; defined specimen; range 10 g–50 g.

A defined living sand dollar with an 8 cm test diameter and 25 g mass. Species and maturity vary; short spines are included visually but do not define the rigid test span.

Smithsonian Ocean — Sea urchins and sand dollars

The marked defined live mass is calibrated. Unmeasured illustration details are representative.

Measurement details

Why these numbers?

Compare 25 grams with the live mass of a sand dollar. The notes below explain how each value was chosen.

25 grams

25 g

Mass · definition

The quantity is exact as entered. Comparisons use the clearly stated specimen, model or nominal measurement.

Sand dollar

25 g

Defined live mass · defined specimen · range 10 g–50 g

A defined living sand dollar with an 8 cm test diameter and 25 g mass. Species and maturity vary; short spines are included visually but do not define the rigid test span.

Comparing
Mass ↔ Defined live mass
Relative size
25 grams is approximately equal to the live mass of a sand dollar.

How to read the visual

The diagram uses the recorded measurements. Details outside the marked spans do not set the scale.

  • We use 25 g for the live mass of a sand dollar; the recorded range is 10 g–50 g.
  • The live mass of a sand dollar: This is an illustrative comparison value, not a claim that every example is the same.
  • The recorded ranges overlap, so the ordering can vary even though the central values differ.

Mass is distinct from weight: an object’s mass stays the same as gravity changes.

0.025 kgkilograms
0.055116 lbpounds
2.5 × 10⁻⁵ ttonnes

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