Prepare Solutions and Dilutions

These calculators help you make up a solution. Work out the mass to weigh for a molarity, the volumes for a dilution ratio or a serial dilution, the water for an alcohol dilution, buffer recipes and phosphate buffer salts, the pH of a solution, and convert between concentration units, ppm and specific gravity.

Tools in this group

• Alcohol Dilution Calculator — Enter the starting strength, the target strength and a volume to get the water to add, in % ABV or US proof.
• Buffer Calculator — Pick a buffer, a target pH and a volume to get the amounts of the acid and base forms, or find the pH from their concentrations.
• Concentration Calculator and Converter — Enter a concentration and the molar mass to see it in molar, mass per volume, percent and ppm units at once.
• Calculate Dilution Ratio and Dilution Factor — Pick how your 1:X ratio is read, then get the concentrate and diluent volumes, the dilution factor or the percent.
• Molarity Calculator — Find the mass to weigh out, the molarity of a solution or the molarity of a concentrated stock; type a formula or the molecular weight.
• pH Calculator — Convert between pH, pOH, hydrogen and hydroxide ion concentration, or find the pH of a strong or weak acid or base.
• Phosphate Buffer Calculator — Pick the pH, concentration and volume to get the grams of each phosphate salt, the stock volumes to mix, or a PBS recipe.
• PPM Calculator (Parts per Million) — Convert ppm to ppb, percent and mg/L, work out ppm from the amounts you weighed, or convert gas ppm to mg/m³.
• Serial Dilution Calculator — Enter the starting concentration, the dilution factor and the number of tubes to get the volumes and concentration of each tube.
• Specific Gravity Calculator — Convert density to specific gravity at a chosen water temperature, specific gravity to density, or API gravity to SG.