• Moles to Liters Calculator (Gas at STP)
    Convert moles of gas to liters at STP using the molar volume (22.4 L/mol). Fast, accurate moles-to-volume calculator for chemistry problems.
  • mg/L to ppm Conversion Calculator
    Convert milligrams per liter (mg/L) to parts per million (ppm) for dilute aqueous solutions. Adjust for solution density. Also shows ppb.
  • pH of Weak Base Calculator
    Calculate the pH, pOH and [OH⁻] of a weak base solution from its Kb and concentration using the square-root approximation [OH⁻] = √(Kb·C).
  • Nernst Equation Calculator
    Calculate cell potential (EMF) with the Nernst equation at 25°C. Enter standard potential E°, electrons transferred n, and reaction quotient Q.
  • RNA Concentration Calculator
    Calculate RNA concentration from A260 absorbance using the 40 ng/µL factor and dilution. Get ng/µL and total RNA yield in µg instantly.
  • pH After Mixing Strong Acid and Base Calculator
    Calculate the pH after mixing a strong acid and strong base. Enter concentrations and volumes to find excess ions, ion concentration, and final pH.
  • Mass to Moles Calculator
    Convert grams to moles instantly. Enter the mass and molar mass to find the number of moles using n = m / M. Free chemistry calculator.
  • Equilibrium Constant (Kc) Calculator
    Calculate the equilibrium constant Kc from product and reactant molar concentrations and their stoichiometric coefficients. Free chemistry tool.
  • Solubility Product (Ksp) Calculator
    Calculate the solubility product Ksp from equilibrium ion concentrations for any salt AaBb. Enter ion molarities and stoichiometric coefficients to get Ksp and pKsp.
  • Molarity to Percent Concentration Calculator
    Convert molarity (mol/L) to percent concentration (% w/v) using molecular weight. Free chemistry calculator with the formula %w/v = M x MW / 10.
  • %w/v to Molarity Calculator
    Convert a percent weight/volume (%w/v) concentration to molarity (mol/L) instantly. Enter the %w/v and molar mass to get the molar concentration.
  • Limiting Reagent Calculator
    Find the limiting reagent of any reaction. Enter the moles and stoichiometric coefficient of each reactant to see which runs out first.
  • Number of Molecules Calculator
    Calculate the number of molecules in a sample from its mass in grams and molar mass using Avogadro number (6.022×10²³). Free chemistry tool.
  • Molarity from Grams and Volume Calculator
    Calculate molarity (mol/L) from grams of solute, molar mass, and solution volume. Free chemistry tool using M = (mass / molar mass) / volume.
  • Percent Composition of a Compound Calculator
    Calculate the percent composition by mass of an element in a chemical compound using number of atoms, atomic mass, and molar mass.
  • Grams to Moles Calculator
    Convert grams to moles instantly. Enter the mass and molar mass to find the amount of substance using n = mass / molar mass. Free chemistry tool.
  • Reaction Stoichiometry Mass Calculator
    Calculate the mass of product formed from a reactant using molar masses and balanced equation coefficients. Free stoichiometry calculator.
  • Percent Yield Calculator
    Calculate the percent yield of a chemical reaction from the actual and theoretical yield. Free chemistry calculator with formula and worked example.
  • Mole Ratio Calculator
    Free stoichiometry mole ratio calculator. Convert moles of substance A to moles of B using balanced equation coefficients. Fast, accurate, and easy.
  • mg/L to Molarity Calculator
    Convert a concentration in mg/L to molarity (mol/L) using the molar mass. Get results in M, mM, and µM instantly with this free calculator.
  • pOH Calculator from [OH⁻]
    Calculate pOH from hydroxide ion concentration using pOH = -log10([OH-]). Instantly find pOH and the corresponding pH at 25°C.
  • Theoretical Yield Calculator
    Calculate the theoretical yield in grams from moles of limiting reactant, reaction coefficients, and molar mass. Optionally find percent yield.
  • Concentration After Dilution Calculator
    Calculate the final concentration of a diluted solution using C2 = (C1 × V1) / V2. Enter initial concentration, initial volume, and final volume.
  • Transmittance to Absorbance Calculator
    Convert percent transmittance (%T) to absorbance (A) instantly using A = -log10(%T/100). Free spectrophotometry calculator for lab and chemistry work.