Online Tool Store
Buffer Recipe Calculator
Pick a buffer system and target pH to calculate the volumes of acid and conjugate base needed, using the Henderson-Hasselbalch equation.
🔒 This tool runs entirely in your browser. Your files are never uploaded to a server.
Example
Buffer Recipe Calculator
Sample: acetate buffer, pH 4.76, 1 L
Example shown — replace it with your own buffer system and target pH.
Target pH
4.76
Volume
1 L, 0.1 M
Result
How it works
- Pick your buffer system and target pH.
- Enter your desired volume and concentration.
- Get the volumes of acid and conjugate base to mix.
The method
The Henderson-Hasselbalch equation calculates the acid-to-base ratio needed for your target pH, based on the buffer system's known pKa.
FAQ
What formula does this use?
The Henderson-Hasselbalch equation, which relates pH to the ratio of a buffer's conjugate base and weak acid concentrations based on the system's pKa.
Why is the target pH close to the pKa?
A buffer works best (resists pH change most effectively) when the target pH is within about 1 unit of the pKa, since that's where the acid/base ratio stays balanced enough to absorb added acid or base.
Does this account for ionic strength or temperature effects?
No — this gives a standard Henderson-Hasselbalch estimate; for precision work, verify the final pH with a calibrated meter after mixing.
How we compare
| Feature | Online Tool Store | Manual Henderson-Hasselbalch calculation | Lab buffer prep software |
|---|---|---|---|
| No software install | Yes | Yes | No |
| Quick to start | Yes | Slow | Setup required |
| Free to use | Yes | Free | Often paid |
For a quick prep calculation without opening lab software, this saves working the equation by hand each time.