Drybench Calc.
Dilution calculator (C1V1 = C2V2)
The stock volume and diluent for a dilution, with ng/µL to nM and percent to molar conversions handled by the units.
C1V1 dilution
C1V1 = C2V2: give three values and the fourth follows, with the diluent to add.
Convert units
This action changes the number and unit together, preserving the physical quantity. The unit menu above continues to assign a unit to the entered number.
Convert units
This action changes the number and unit together, preserving the physical quantity. The unit menu above continues to assign a unit to the entered number.
Convert units
This action changes the number and unit together, preserving the physical quantity. The unit menu above continues to assign a unit to the entered number.
Convert units
This action changes the number and unit together, preserving the physical quantity. The unit menu above continues to assign a unit to the entered number.
Concentration in mass units needs a formula weight to convert to molar; both sides are converted the same way.
Preparation
Plan an intermediate dilution
When the direct stock volume is too small, check a single intermediate against your transfer range, available stock and carrier-solvent limit.
Answer
- Take
- 1µL
- Dilution by C1V1 = C2V2
- Diluent to add
- 199µL
- Dilution factor
- 200×
Open in the bench sheetThe bench sheet carries these inputs and offers the other calculators.
Worked example
- 10 mM stock to 50 µM in 200 µL: V1 = 50 µM × 200 µL / 10 mM = 1.0 µL of stock and 199.0 µL of diluent, a 200-fold dilution.
- 50 ng/µL of a 25 kDa protein is 2 µM, so 100 nM in 1 mL takes 50 µL: the units convert through the molar mass.
Method
- Dilution by C1V1 = C2V2. src/lib/dilution/c1v1.ts 1.0.0Checked against Python's exact rational arithmetic (fractions.Fraction) to nine significant figures on 31 fixtures (6 October 2026).
Limits
- For research and education only, and not medical advice: the stock, dilution and buffer calculations here are not for dosing or clinical preparation.