50+ free calculators

Lab Calculator & Converter

Dilution, HPLC, UV spectroscopy, solution preparation and unit converters β€” all free, no sign up required.

πŸ”¬ Analytical Validation Tools

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Purity Correction Calculator

Correct weighed amount for purity of reference standard.

βœ… Ready Inputs: target mass, % purity (or potency). Outputs adjusted mass to weigh.
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Yield Calculator

Calculate percent yield for reactions and extractions.

βœ… Ready Calculate % yield or % w/v. Also see Percent Recovery Calculator below.
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Assay Calculation

Calculate assay percentage against a reference standard.

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Calibration Curve & Unknown ConcentrationNew

Fit a linear calibration curve and calculate unknown sample concentration.

βœ… Ready Build a curve from standards, then solve for an unknown sample's concentration.
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LOD / LOQ CalculatorNew

Calculate Limit of Detection and Limit of Quantification.

βœ… Ready Inputs: SD of blank/residual (Οƒ), calibration slope (S).
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Precision Calculator (%RSD)New

Calculate mean, SD, and %RSD from replicate measurements.

βœ… Ready Inputs: up to 8 replicate values.
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Percent Recovery CalculatorNew

Assess method accuracy by comparing measured vs. expected amounts.

βœ… Ready Inputs: measured amount, expected/spiked amount.
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Standard Addition CalculatorNew

Calculate unknown concentration for matrix-affected samples.

βœ… Ready Single-point standard addition method. Inputs: Vx, A1, Vs, Cs, A2.
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Signal-to-Noise RatioNew

Calculate S/N from peak height and baseline noise.

βœ… Ready USP/ICH definition: S/N = 2H/h.
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System Suitability CalculatorNew

Check replicate precision (%RSD) against your acceptance limit.

βœ… Ready Inputs: up to 6 replicate injections, %RSD acceptance limit. Gives Pass/Fail.

πŸ”€ Chromatography Tools

HPLC & Method Development

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Retention Factor (k')

Calculate HPLC retention factor k' with pass/fail guidance.

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Mobile Phase Preparation

Calculate volumes for HPLC mobile phase. Up to 4 components, any ratio.

βœ… Ready Inputs: % organic, total volume. Outputs exact volumes of each solvent.
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Chromatographic Resolution (Rs)New

Calculate peak resolution from retention times and baseline widths.

βœ… Ready Inputs: t1, t2, W1, W2. Gives Rs with pass/fail assessment.
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Plate Number CalculatorNew

Calculate theoretical plates (column efficiency) from retention time and peak width.

βœ… Ready Baseline or half-height width methods supported.
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Tailing Factor CalculatorNew

Calculate USP tailing factor (Tf) to assess peak symmetry.

βœ… Ready Inputs: width at 5% height, front half-width. Gives Tf with assessment.
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Internal Standard QuantificationNew

Determine response factor and calculate unknown concentration.

βœ… Ready Two-step: determine RF from standard, then apply to sample.
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External Standard QuantificationNew

Calculate concentration from a single external standard comparison.

βœ… Ready Inputs: standard area/conc, sample area.
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Mobile Phase Mixing RatioNew

Calculate solvent volumes for binary or ternary mobile phase ratios.

βœ… Ready Inputs: ratio (A:B or A:B:C), total volume needed.
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HPLC Method TransferNew

Scale flow rate and injection volume between column dimensions.

βœ… Ready Same particle size, different column length/diameter.
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LC to UHPLC Method TransferNew

Scale flow rate, injection volume, and run time to a UHPLC column.

βœ… Ready Accounts for both column volume and particle size difference.
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Gradient Delay VolumeNew

Calculate HPLC dwell volume, dwell time, or flow rate for method transfer.

βœ… Ready Inputs: flow rate, dwell time, or dwell volume. Solves any of the three.
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Column Volume CalculatorNew

Calculate chromatography column volume from diameter and length.

βœ… Ready Inputs: ID, length, or CV. Solves any of the three.

Flash, Prep & TLC

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TLC to Flash Method ConverterNew

Estimate flash elution volume from a TLC Rf value.

βœ… Ready Inputs: target Rf, optional nearby impurity Rf.
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Prep HPLC Scale-Up CalculatorNew

Scale flow rate and injection mass to a preparative column.

βœ… Ready Inputs: analytical column ID/flow/mass, prep column ID.
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Column Loading CalculatorNew

Calculate max sample load or required silica mass.

βœ… Ready Inputs: silica mass or sample mass, loading ratio.
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Gradient Conversion (Time ↔ CV)New

Convert flash gradient steps between time and column volumes.

βœ… Ready Inputs: flow rate, column volume, time or CV.
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Flash Fraction PlannerNew

Plan number of fractions, time per fraction, and run time.

βœ… Ready Inputs: total run volume, flow rate, tube volume.
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Solvent System SelectorNew

Predict solvent %B for a target Rf from two test runs.

βœ… Ready Inputs: two (%B, Rf) test points, target Rf.
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Retention Volume / CV CalculatorNew

Convert observed elution volume to column-volume units.

βœ… Ready Inputs: column volume, elution volume or CV retention.
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HPTLC Rf CalculatorNew

Calculate Rf from compound and solvent front migration distances.

βœ… Ready Inputs: compound distance, solvent front distance.

Gas Chromatography

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GC Retention Index CalculatorNew

Calculate Kovats retention index for isothermal GC.

βœ… Ready Inputs: compound and bracketing n-alkane retention times.
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GC Split Ratio CalculatorNew

Calculate split ratio, split flow, or column flow rate.

βœ… Ready Inputs: column flow, split flow, or split ratio (solve any).

🌈 Spectroscopy & Mass Tools

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Beer–Lambert Law CalculatorNew

Solve for absorbance, concentration, molar absorptivity, or path length.

βœ… Ready Inputs: A, Ξ΅, c, l. Solves any of the four.
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Absorbance ↔ TransmittanceNew

Convert instantly between absorbance and percent transmittance.

βœ… Ready Inputs: A or %T. Converts either direction.
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UV Peak / Purity HelperNew

Check for co-elution using a simplified two-wavelength ratio comparison.

βœ… Ready Inputs: absorbance at 2 wavelengths, 3 points across the peak.
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LCMS Adduct Mass CalculatorNew

Calculate common LC-MS adduct m/z values from neutral mass.

βœ… Ready Inputs: neutral monoisotopic mass. Outputs 9 common adducts.
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Karl Fischer Water ContentNew

Calculate water content and %w/w from KF titration data.

βœ… Ready Inputs: titrant volume, KF titer, sample weight.
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NMR Residual Solvent ReferenceNew

Look up residual solvent and water peaks for 8 common NMR solvents.

βœ… Ready Select a solvent to see ΒΉH, ΒΉΒ³C, and water shifts (Gottlieb et al. 1997).
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FTIR Functional Group MatchNew

Find candidate functional groups for an observed IR wavenumber.

βœ… Ready Inputs: wavenumber (cm⁻¹). Returns matching functional group ranges.

🧫 Solution / Preparation Tools

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Simple Dilution (C1V1 = C2V2)

Calculate volumes for simple dilutions. Solve any of the four variables.

βœ… Ready Inputs: C1, V1, C2, V2. Solves any variable. Handles ΞΌL/mL/L unit mixing.
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Serial Dilution

Calculate concentrations across serial dilution steps. Up to 20 steps.

βœ… Ready Inputs: stock conc, dilution factor, tube volume, steps. Outputs full table.
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Concentration Converter

Convert between mg/mL, ΞΌg/mL, molarity, mmol/L and % w/v.

βœ… Ready Inputs: value, MW. Converts 7 units incl. mol/L, % w/v, mg/mL, ΞΌg/mL.
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Buffer Preparation Calculator

Prepare phosphate, acetate, Tris, HEPES and other buffers at any pH and molarity.

βœ… Ready Inputs: pH, volume, buffer system. Outputs exact masses to weigh.
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Standard Solution Preparation

Calculate how to prepare stock and working standard solutions from solid or liquid.

Prepare from a solid reagent (mass needed) or a concentrated liquid stock (volume needed).
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Ionic Strength CalculatorNew

Calculate solution ionic strength from ion concentrations and charges.

βœ… Ready Inputs: up to 5 ionic species (concentration + charge).
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Solubility CalculatorNew

Calculate max soluble amount or min solvent needed.

βœ… Ready Inputs: solubility (g/100mL), solvent volume or solute mass.
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Hydrated Salt CalculatorNew

Calculate hydrate molar mass, %water, and mass needed.

βœ… Ready Inputs: anhydrous molar mass, waters of crystallization, target mass.
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Neutralization CalculatorNew

Calculate acid/base volume or concentration for neutralization.

βœ… Ready Inputs: acid/base concentration, volume, valence. Solves any.

🧬 Biology & Molecular Tools

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PCR Master Mix CalculatorNew

Scale PCR component volumes for multiple reactions with overage.

βœ… Ready Inputs: per-reaction volumes, reaction count, overage %.
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Primer Tm CalculatorNew

Calculate primer melting temperature from sequence.

βœ… Ready Inputs: primer sequence, Na⁺ concentration.
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DNA/RNA Concentration CalculatorNew

Calculate nucleic acid concentration and purity from A260/A280.

βœ… Ready Inputs: A260, dilution factor, optional A280 for purity.

🌍 Environmental & General Lab Tools

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Unit Converter

Convert volume, mass, temperature, pressure, and time instantly.

βœ… Ready Convert volume, mass, temperature, pressure, and time. No input limit.
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Centrifuge RPM ↔ RCFNew

Convert between rotor speed (RPM) and relative centrifugal force (Γ—g).

βœ… Ready Inputs: rotor radius, RPM or RCF. Solves either direction.
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Carbon to Nitrogen RatioNew

Calculate combined C:N ratio for composting or soil amendment.

βœ… Ready Inputs: mass, %C, %N for up to 2 materials.
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COD / BOD CalculatorNew

Calculate chemical or biological oxygen demand for water quality.

βœ… Ready Two modes: COD via titration, BOD via DO depletion.

Documentation

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Lab Notebook Template GeneratorNew

AI-generated structured notebook entries for any experiment type.

Describe your experiment β€” AI structures a notebook entry with objective, materials, method and results sections.