Svedberg Equation Calculator

Turn centrifuge measurements into reliable molar masses. Built for quick checks and careful unit control. See results instantly, then export them for your notes.

Calculator Inputs

Fields auto-arrange for desktop, tablet, and mobile.

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Sedimentation coefficient, s

1 S = 1×10⁻¹³ seconds.

Diffusion coefficient, D

Use scientific notation for very small values.

Temperature, T

Converted internally to Kelvin.

Solvent density, ρ

Water at room temperature is ~1.0 g/mL.

Partial specific volume, v̄

Typical proteins: ~0.70–0.75 mL/g.

Viscosity, η (optional)

Used to estimate Rₕ via Stokes relation.

CSV PDF

Tip: if you paste values like 6.7e-7, the calculator reads them correctly.

Example Data Table

Sample	s (S)	D (cm^2/s)	T (°C)	ρ (g/mL)	v̄ (mL/g)	M (kDa)	Rh (nm)
Protein-like example	4.3	6.7×10⁻⁷	20	1.0	0.73	57.9	3.20
Smaller macromolecule	2.1	1.2×10⁻⁶	25	1.0	0.72	19.6	1.85
Large complex	12.0	3.0×10⁻⁷	20	1.0	0.74	331	7.6

These examples are illustrative and rounded for readability.

Formula Used

The Svedberg equation links sedimentation and diffusion to molar mass:

M = (s · R · T) / (D · (1 − v̄ · ρ))

s is the sedimentation coefficient.
D is the diffusion coefficient.
R is the gas constant (8.314462618 J/mol·K).
T is absolute temperature in Kelvin.
v̄ and ρ set the buoyancy correction.

How to Use This Calculator

Enter s and choose S or seconds.
Enter D and pick matching diffusion units.
Set temperature, density, and partial specific volume.
Optionally add viscosity to estimate hydrodynamic radius.
Press Compute to view results above the form.
Use the CSV/PDF buttons to export the computed report.

Values are for learning and lab planning, not clinical decisions.

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Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.