How It Works
This calculator works in 4 steps.
Enter the stock recipe
Type each component and its concentration in the stock buffer, or pick a template.
Enter the dilution
Type DF or the target × strength.
Apply the factor to each line
The calculator divides every component by DF.
Read the component table
The calculator lists every component at the working strength in mM and g/L.
The Formula
The formula divides every component concentration by the shared dilution factor.
Cᵢ,final = Cᵢ,stock / DFDF = X_stock / X_final- Cᵢ:
- Concentration of component i
- DF:
- Dilution factor
- X:
- × strength of the buffer
Diluting 10× PBS to 1× (DF = 10) turns 1,370 mM NaCl into 137 mM and 100 mM Na₂HPO₄ into 10 mM.
Conversion Table
The conversion table lists each PBS component at 10×, 1×, and 0.5× strength.
| Component | 10× PBS | 1× PBS | 0.5× PBS |
|---|---|---|---|
| NaCl | 1,370 mM | 137 mM | 68.5 mM |
| KCl | 27 mM | 2.7 mM | 1.35 mM |
| Na₂HPO₄ | 100 mM | 10 mM | 5 mM |
| KH₂PO₄ | 18 mM | 1.8 mM | 0.9 mM |
What Is the Buffer Component Dilution Calculator?
The Buffer Component Dilution Calculator is a tool that returns the final concentration of each component in a buffer after dilution. Every component is divided by the same dilution factor, so the ratios between components stay fixed.
Buffer recipes list each salt, acid, base, and additive with its own concentration. Diluting 10× phosphate-buffered saline (PBS) to 1× gives 137 mM NaCl, 2.7 mM KCl, 10 mM Na₂HPO₄, and 1.8 mM KH₂PO₄. The calculator outputs a component table at any working strength, such as 1×, 0.5×, or 2×.
Common Uses
There are 5 main uses of this calculator.
Methods reporting
Authors report final component concentrations in papers.
Osmolarity checks
Users estimate osmolarity from component levels.
Ionic strength
Biochemists compute ionic strength at working dilution.
Buffer audits
QC staff confirm component levels in prepared batches.
Custom strengths
Researchers prepare 0.5× or 2× buffers for special cases.