Solutions, Concentrations & Lab Prep Calculators

All solutions, concentrations & lab prep calculators in one place.

Molarity Calculator

Calculate molarity, moles, solution volume, dilution, and solute mass with step-by-step unit conversions.

Molality Calculator

Calculate molality, moles of solute, solvent mass, and solute mass, plus freezing point depression and boiling point elevation, with step-by-step unit conversions.

Normality & Equivalent Mass Calculator

Calculate normality, equivalents, solution volume, solute mass, equivalent mass (equivalent weight), and molarity-to-normality conversion, with n-factor presets and step-by-step working.

Solve C1V1=C2V2 for stock concentration, target concentration, stock volume, or final volume, calculate ratio dilutions like 1:10, or build a full serial dilution table and dilution curve, with full step-by-step working.

Serial Dilution Solver

Build a full serial dilution series, solve backwards for the per-step factor and volumes needed to hit a target endpoint, or back-calculate CFU/mL from a plate colony count, with a dilution curve and full step-by-step working.

Mass Percent Concentration

Calculate mass percent concentration (% w/w) from solute and solvent mass, find the solute or solvent mass needed for a target percent, work out dilution water, convert mass percent to molarity, and convert freely between percent, ppm, and ppb, with full step-by-step working.

Volume Percent Concentration

Calculate volume percent concentration (% v/v) from solute and solvent volume, find the solute or solvent volume needed for a target percent, work out dilution volume, convert volume percent to molarity, and convert freely between percent, ppm, and ppb, with full step-by-step working.

Mass-by-Volume Percent

Calculate mass by volume percent concentration (% w/v) from solute mass and solution volume, find the solute mass or solution volume needed for a target percent, work out dilution volume, convert % w/v to molarity, convert % w/v to % w/w using density, and convert freely between percent, ppm, and ppb, with full step-by-step working.

PPM (Parts Per Million) Converter

Convert parts per million to percent, ppb, ppt, mg/L, mg/kg, and molarity, work out the solute mass needed to prepare a target ppm standard solution, and solve ppm dilutions, with full step-by-step working.

PPB (Parts Per Billion) Converter

Convert parts per billion to percent, ppm, ppt, µg/L, µg/kg, and molarity, work out the solute mass needed to prepare a target ppb standard solution, solve ppb dilutions, and convert gas-phase ppb (ppbv) to µg/m³ for air quality, with full step-by-step working.

Mole Fraction Calculator

Find the mole fraction of every component in a mixture of up to eight components from mass and molar mass, convert a solute's mole fraction into molality, molarity, and mass percent, and calculate vapor pressure with Raoult's Law, with full step-by-step working.

Solution Density & Specific Gravity

Calculate solution density from mass and volume, solve for mass or volume, convert density to specific gravity (SG) and back, and get an automatic Baumé degree reading, with multiple water reference temperatures and full step-by-step working.

Solution Blending / Concentration Mixing

Find the resulting concentration when blending two solutions, or work out exactly how much of each stock solution you need to hit a target concentration and volume or mass, using molarity or mass percent, with full step-by-step alligation working.

Stock Solution Reconstitution Solver

Find how much diluent to add to a powder or lyophilized vial to hit a target concentration, work out the concentration you already made, or calculate the exact draw volume for a dose, with purity, powder displacement, molarity conversion, and full step-by-step working.

Osmolality & Osmolarity Calculator

Calculate osmolarity (mOsm/L) and osmolality (mOsm/kg) from molarity or solute mass with a van't Hoff dissociation factor and tonicity check, or work out calculated serum osmolarity and the osmolar gap from sodium, glucose, and BUN, with full step-by-step working.

Ionic Strength Calculator

Calculate the ionic strength of a solution from a custom ion list or a common salt preset, find Debye-Hückel and Davies activity coefficients, and solve ionic strength dilutions, with a contribution chart and full step-by-step working.

Molarity to PPM Converter

Convert molarity (mol/L) to ppm and mg/L, convert ppm back to molarity, work out how much solute to weigh for a target molar or ppm solution, and solve stock-to-working ppm dilutions, with a common-solute quick-fill list and full step-by-step working.

PPM to Molarity Converter

Convert ppm and mg/L into molarity (mol/L), convert molarity back to ppm, find the solute mass needed for a target ppm or molar standard, and solve stock-to-working ppm dilutions, with a common-solute quick-fill list and full step-by-step working.

Mass Percentage to Molarity Converter

Convert mass percent (% w/w) into molarity (mol/L), convert molarity back to mass percent, find the solute mass needed to prepare a target mass % solution, and solve stock-to-working mass % dilutions, with a common-solute quick-fill list and full step-by-step working.

Specific Gravity to Molarity Converter

Convert specific gravity (SG) and mass percent into molarity (mol/L), convert molarity back to SG and mass percent, find the solute mass needed to prepare a target solution by volume, and solve stock-to-working SG dilutions, with selectable water references, a common-solute quick-fill list, and full step-by-step working.

Buffer Solution Volume & Mass Calculator

Work out exactly how much acid and conjugate base to weigh out or mix from stock solutions to make a buffer at any target pH, check the pH of a buffer you've already made, and dilute a buffer stock without shifting its pH, with a built-in library of common buffer systems (acetate, phosphate, Tris, citrate, bicarbonate, HEPES, MES, borate, glycine, ammonia) and full step-by-step working.

Solvent Evaporation & Concentration Increase

Find the new concentration after solvent evaporates from a solution, work out how much solvent needs to evaporate to hit a target concentration or mass percent (% w/w), and estimate the evaporation time from a known rate, with full step-by-step working.