• mEq to mg Calculator
    Convert milliequivalents (mEq) to milligrams (mg) for electrolytes like sodium, potassium, calcium and magnesium using atomic weight and valence.
  • Molar Solubility from Ksp Calculator
    Calculate the molar solubility (s) of a sparingly soluble salt from its Ksp and stoichiometry. Free chemistry tool with worked example and formula.
  • Milliliters to Grams Calculator
    Convert milliliters (mL) to grams using density. Enter volume and density to instantly get mass in grams and kilograms with the formula m = V × ρ.
  • pH of Weak Acid Calculator
    Calculate the pH of a weak acid solution from its Ka and initial concentration using the approximation [H⁺] = √(Ka·C). Free chemistry tool.
  • Concentrated Acid Molarity Calculator
    Calculate the molarity (mol/L) of a concentrated acid or stock solution from its mass percent, density, and molar mass with this free chemistry tool.
  • Essential Oil Dilution Calculator
    Calculate how many drops of essential oil to add to your carrier oil for a safe dilution percentage. Fast, accurate drops-per-ml blending tool.
  • pH of Strong Base Calculator
    Calculate the pH and pOH of a strong base solution from its molar concentration and number of hydroxide ions per formula unit at 25 °C.
  • Molarity to mg/mL Calculator
    Convert molarity (mol/L) to mg/mL using molecular weight. Free online molarity to mg/mL calculator for lab solution preparation and chemistry.
  • Final Volume After Dilution Calculator
    Calculate the final volume (V2) after diluting a solution using V2 = C1·V1 / C2. Find how much solvent to add to reach a target concentration.
  • Hydroxide Ion Concentration Calculator
    Convert pOH to hydroxide ion concentration [OH⁻] or back. Calculates [OH⁻], pOH, pH and [H⁺] instantly using [OH⁻] = 10^(−pOH).
  • Percent Error Calculator (Chemistry)
    Calculate percent error in chemistry from experimental and theoretical values. Free percent error calculator with formula, worked example, and FAQ.
  • Molarity of Concentrated Solution from Percent
    Calculate the molarity of a concentrated solution from its mass percent (% w/w), density, and molar mass using M = (10 × %w/w × density) / MW.
  • Reagent Molarity Calculator
    Calculate the molarity (mol/L) of a concentrated acid or reagent solution from its density, percent weight (%w/w) purity, and molar mass.
  • Molar Mass from Mass and Moles Calculator
    Calculate molar mass (g/mol) from a known mass and number of moles using M = mass ÷ moles. Fast, accurate chemistry tool with worked examples.
  • PPM to PPB Calculator
    Convert parts per million (ppm) to parts per billion (ppb) instantly. Just multiply by 1000. Free, accurate ppm to ppb conversion calculator.
  • Grams per Liter Calculator (g/L)
    Calculate concentration in grams per liter (g/L) by dividing mass in grams by volume in liters. Fast, accurate, and free online tool.
  • Reef Tank Salt Mix Calculator
    Calculate how much reef salt mix to add to your water to hit a target salinity (ppt). Enter water volume, target salinity, and your salt's dose rate.
  • ABV Calculator from Original & Final Gravity
    Calculate alcohol by volume (ABV%) for beer, wine, mead, or cider from your original gravity (OG) and final gravity (FG) readings.
  • pH to pOH Calculator
    Convert pH to pOH instantly with this free calculator. Uses pOH = 14 − pH at 25°C and shows H⁺ and OH⁻ ion concentrations.
  • ABV to Proof Calculator
    Convert alcohol by volume (ABV %) to US proof instantly. US proof equals ABV multiplied by 2. Free, fast ABV to proof conversion tool.
  • PPB Calculator
    Calculate concentration in parts per billion (ppb) from mass of solute and mass of solution. Also shows ppm and percent. Free, instant chemistry tool.
  • Weight Percent to Molarity Calculator
    Convert weight percent (wt%) to molarity (mol/L) using solution density and solute molar mass. Free chemistry concentration calculator with the formula explained.
  • pH Buffer Preparation Calculator
    Calculate how much weak acid and conjugate base to mix for a target pH buffer using the Henderson-Hasselbalch equation. Get ratio, concentration & moles.
  • Percent Dilution Calculator
    Calculate the final percent concentration after adding diluent. Uses C2 = C1·V1/(V1+V_added) to find diluted strength, total volume, and dilution factor.