1. What is the Molecular Weight To Size Calculation?

The molecular weight to size calculation provides an approximate estimation of molecular size from molecular weight. This is based on the assumption that molecules are roughly spherical and have similar densities.

2. How Does the Calculator Work?

The calculator uses the following equation:

Where:

• \( Size \) — Estimated molecular size in nanometers (nm)
• \( MW \) — Molecular weight in Daltons (Da)

Explanation: The equation assumes volume scales with molecular weight and that molecules are roughly spherical, giving this cubic root relationship.

3. Importance of Size Estimation

Details: Molecular size estimation is important for understanding diffusion rates, membrane permeability, and steric effects in biochemical systems.

4. Using the Calculator

Tips: Enter molecular weight in Daltons (Da). The value must be positive. The result will be an approximate size in nanometers.

5. Frequently Asked Questions (FAQ)

Q1: How accurate is this estimation?
A: This is a rough approximation. Actual size depends on molecular shape and density, which can vary significantly.

Q2: What are typical molecular sizes?
A: Small molecules (100-500 Da) are typically 0.5-1 nm, proteins (10-100 kDa) are 2-6 nm, and large complexes can be 10+ nm.

Q3: When would this estimation not apply?
A: For very elongated or flat molecules, or molecules with unusual density (like lipids).

Q4: Can this be used for nanoparticles?
A: The approximation becomes less accurate for very large particles where shape factors become more important.

Q5: How does hydration affect size?
A: Hydration shells can increase effective size by 0.2-0.5 nm, which isn't accounted for in this simple calculation.