Calculators

Free tools for everyday bench work. Full precision internally, rounded only at display.

• Molarity

  Mass ↔ concentration ↔ volume, with MW lookup by name or formula.

• Dilution

  C₁V₁ = C₂V₂ solver with dilution factor, diluent to add, and a serial dilution planner.

• Solution prep from stock

  Stock molarity from density and assay %, and the volume of concentrate to pipette — CoA values supported.

• Percent concentration

  Prepare w/v, w/w and v/v solutions and interconvert with mg/mL, g/L and ppm — density-aware.

• ppm / ppb converter

  %, ppth, ppm, ppb, ppt, mg/kg and mg/L in one table — bridged by an explicit solution density.

• Molecular weight

  Molar mass from a formula or reagent name, with elemental composition and the hydrated vs anhydrous comparison.

• Dry basis correction

  Loss on drying from weigh-in and weigh-out, and a result moved between the as-received and dry bases.

• Buffer preparation

  Acid and conjugate base amounts for a target pH by Henderson–Hasselbalch, with pKa corrected to your working temperature.

• Mean, SD and %RSD

  Mean, standard deviation, %RSD and a confidence interval on the mean from pasted replicate results.

• Calibration curve

  Linear regression from your standards with residuals, and an unknown's concentration read back off the line.

• LOD and LOQ

  Detection and quantitation limits by ICH Q2(R2) — every σ your data supports side by side, plus the signal-to-noise route.

• Spike recovery

  Percent recovery from a spiked sample, corrected for the volume the spike adds, with mean recovery and %RSD across an accuracy study.