Dilution Factor Calculator
Calculate how much your solution has been diluted. Determine dilution factor, fold dilution, and final concentration for any dilution protocol.
Volume of stock solution in mL
Total volume after dilution in mL
Stock concentration (optional, for concentration calculation)
Volume of diluent added (V2 - V1) - optional verification
What is dilution factor?
Dilution factor (DF) measures how much a solution has been diluted. It is the ratio of final volume to initial volume: DF = V2/V1. A 10-fold dilution (DF = 10) means the concentration is reduced by factor of 10. For example, taking 1 mL of stock and diluting to 10 mL gives DF = 10.
How do you calculate dilution factor?
DF = V2 / V1 = Final Volume / Initial Volume. For serial dilutions, multiply all dilution factors: total DF = DF1 × DF2 × DF3. Example: 1 mL → 9 mL (first, DF=10), then 1 mL → 99 mL (second, DF=100): total DF = 10 × 100 = 1000.
What is the difference between fold and factor?
Dilution factor (DF) and fold dilution are essentially the same: DF = 10 means "10-fold dilution." The term "fold" means multiplier: a 10-fold dilution reduces concentration to 1/10. Some fields use "fold" differently, so clarify: "10-fold dilution" usually means 10× more diluent than original, giving 1:10 ratio.
How do you calculate final concentration?
Use C1V1 = C2V2, rearranged to C2 = C1 × (V1/V2) = C1/DF. Example: 1 M stock, 10-fold dilution: C2 = 1 M / 10 = 0.1 M. For the same formula in mg/mL, ppm, or any unit, the ratio depends only on volume, not concentration units.
What is a serial dilution?
Serial dilution repeatedly dilutes a sample in steps. Common in microbiology, ELISA, and qPCR. Each step uses the same dilution factor, creating a logarithmic series. A 10-fold serial dilution for 6 steps: 10⁻¹, 10⁻², 10⁻³... 10⁻⁶ (1,000,000-fold total). This creates standards over many orders of magnitude.