Use Buffer Calculator to choose a common buffer, set target pH and strength, choose salt or hydrate forms, and scale a starting recipe by final volume. The search field accepts common names, abbreviations, salt names, and formulas.
Useful Checks
Buffer Calculator separates pH-calculated buffers from fixed recipe templates so PBS, TAE, TBE, SSC, and TE are not forced into the wrong Henderson-Hasselbalch model.
Use the buffer search field for common names, abbreviations, salt names, and formulas such as KPi, KH2PO4, NaH2PO4, HEPES, TBS, or TAE.
Check the pH suitability status before weighing. A buffer can calculate mathematically but still be a poor choice for the requested pH.
Use the Molarity Calculator handoff when you want to edit imported components, change units, or build a larger multi-solute recipe around the buffer components.
Minimum Inputs Needed
Buffer name; the buffer list is searchable by full name, abbreviation, salt pair, formula, and common publication name.
Target pH from the buffer-specific pKa/useful-range slider.
Target concentration for calculated buffers, or recipe strength for template buffers, using the strength sliders or exact number fields.
Final volume in mL, with a 0-1000 mL slider and marked points at 15, 50, 100, 150, 250, 500, 750, and 1000 mL.
Dry component form or stock concentration when relevant.
What The Result Means
The suitability text tells you whether the target pH is inside the practical range stored for that buffer.
Near the edge of a range, verify the choice against the assay protocol and consider nearby buffers.
Outside the practical range, the calculator suggests alternatives where possible.
The recipe is a starting calculation, not a replacement for pH meter adjustment and protocol verification.
Calculated Buffers Versus Recipe Templates
Sodium phosphate, potassium phosphate, acetate, carbonate-bicarbonate, and citrate use Henderson-Hasselbalch acid/base ratios where that model is appropriate. Citrate uses the nearest citric acid pKa for the target pH and reports the selected pKa. Tris, HEPES, MES, MOPS, PIPES, Bis-Tris, Bis-Tris propane, ADA, ACES, BES, TES, HEPPS/EPPS, MOPSO, DIPSO, TAPSO, POPSO, HEPPSO, Bicine, Tricine, TAPS, CHES, CAPS, CAPSO, imidazole, succinate, maleate, borate, and glycine buffers are handled as single buffer compounds that should be dissolved below final volume and pH-adjusted.
McIlvaine buffer is treated as a citrate-phosphate stock-mixing recipe, because that common publication name refers to citric acid plus disodium hydrogen phosphate stocks. PBS, TBS, TAE, TBE, SSC, and TE are fixed recipe templates. Recipes that use liquid acids expose % w/w and density inputs so the calculated volume can match the acid stock in the lab. Their components scale by final volume and recipe strength, but changing the pH should be treated as a protocol decision, not just a calculator field.
Example
For "50 mM potassium phosphate buffer, pH 7.4, 1 L", the calculator uses the phosphate pKa, splits the total phosphate between monobasic and dibasic potassium phosphate, reports the component masses for the chosen hydrate forms, and flags whether pH 7.4 is in range.
Wet-lab caution: Always confirm exact salt or hydrate form, supplier molecular weight, pH meter calibration, temperature, solubility, and biological compatibility. Dissolve components in less than the final volume, adjust pH, then bring to final volume.