Complete Free Lab Analytical Calculator Guide — Dilution, HPLC, UV Spectroscopy and More
If you work in an analytical lab, you know how much time goes into routine calculations. Dilutions before every experiment. HPLC parameters after every run. UV absorbance conversions in between. And somehow, most researchers are still doing these on scattered websites, outdated Excel sheets, or worse — by hand.
Scitero brings all these calculations into one free, no-sign-up platform. This guide walks you through every lab calculator available — what it does, when to use it, and the formula behind it.
1. Dilution & Concentration Calculators
Simple Dilution — C1V1 = C2V2
The most used calculation in any wet lab. Whether you are preparing a working standard from a stock solution or diluting a sample before injection, the C1V1 formula is your starting point.
Enter any three values and the calculator gives you the fourth. Works with any concentration unit as long as both sides match — mg/mL, μg/mL, molarity, or % w/v.
💡 Practical tip
Always prepare slightly more volume than needed. If you need 10 mL of working standard, calculate for 12 mL. It accounts for dead volume in pipettes and syringes.
Serial Dilution Calculator
Used in method development, standard curve preparation, and microbiological assays. You define the starting concentration, the dilution factor, and the number of steps — the calculator gives you the concentration at each level.
This is especially useful when preparing a 5-point or 6-point calibration curve for HPLC or spectrophotometry methods.
Concentration Converter
Switching between mg/mL, μg/mL, molarity, and % w/v is something every analyst does daily. This converter handles all four units in both directions. Enter a value in one unit, get it instantly in all others.
2. Weighing & Purity Calculators
Purity Correction Calculator
Reference standards and analytical grade reagents are never 100% pure. When your certificate of analysis says 99.2% purity, the amount you actually weigh needs to be corrected upward to get the true potency you need.
Skipping this step is one of the most common sources of systematic error in analytical methods. This calculator makes it a 5-second task.
Potency Based Weighing Calculator
Used when working with antibiotic standards, biological reference materials, or any substance where potency is expressed in units per mg rather than a simple purity percentage. Enter the stated potency and required activity — get the exact weight to measure.
3. Solution Preparation
Mobile Phase Preparation
Getting the mobile phase ratio right is critical for retention time reproducibility in HPLC. Enter the total volume needed and the ratio of each component — acetonitrile, water, buffer, methanol — and the calculator gives you exact volumes for each.
Buffer Preparation
Prepare phosphate, acetate, citrate and other common buffers at any pH and concentration. The calculator uses Henderson-Hasselbalch to give you the right ratio of acid to conjugate base, then scales to your required volume.
Standard Solution Preparation
From weighing the primary standard to preparing the final working concentration — this calculator walks through each step so your standard matches your method requirements exactly.
4. Method & Analysis Calculators
LOD and LOQ Calculator
Limit of Detection and Limit of Quantification are required parameters in any analytical method validation. The ICH Q2(R1) approach uses the standard deviation of the response and the slope of the calibration curve.
Enter your calibration data — the calculator handles the rest and gives you both values with the working shown.
Yield Calculator
Calculate percentage yield for synthesis reactions, extractions, and recovery experiments. Enter theoretical and actual yield — get percentage yield instantly. Useful for both chemistry synthesis and sample preparation validation.
% Recovery Calculator
Essential for method validation. Enter the spiked amount and the measured amount — the calculator gives you percentage recovery. Acceptable recovery ranges vary by method — typically 98–102% for assay and 70–120% for trace analysis.
5. HPLC Calculations
These five parameters define the performance of your chromatographic method. Every analyst running HPLC needs to calculate them — during method development, validation, and system suitability checks.
Retention Factor (k')
Where tR is retention time of the peak and t0 is the dead time. A k' between 2 and 10 is considered ideal for most methods.
Resolution (Rs)
Resolution greater than 1.5 indicates baseline separation. This calculator takes the retention times and peak widths of two adjacent peaks and gives you Rs directly.
Theoretical Plates (N)
A measure of column efficiency. Higher N means sharper peaks and better separation. Most regulatory guidelines require N greater than 2000 for a valid system suitability.
Tailing Factor
Where w0.05 is peak width at 5% height and f is the distance from peak front to peak maximum. A tailing factor between 0.8 and 1.5 is generally acceptable.
Assay Calculation
Calculate the percentage assay of your sample against a reference standard. Enter the peak areas, weights, and potency values — the calculator gives you the assay result ready for your analytical report.
6. UV Spectroscopy Calculators
Beer-Lambert Law
The foundation of UV spectrophotometry. Enter absorbance, path length, and molar absorptivity to get concentration — or enter concentration to get expected absorbance. Used for protein quantification, drug analysis, and purity checks.
Molar Absorptivity (ε)
Calculate the molar absorptivity of your compound from absorbance, concentration, and path length measurements. This value is a characteristic property of each compound at a specific wavelength.
Transmittance ↔ Absorbance Converter
Some older instruments report transmittance instead of absorbance. This converter switches between the two instantly.
7. Unit Converters
Six converters covering the units analytical chemists use every day — volume (μL, mL, L), mass (μg, mg, g, kg), temperature (Celsius, Fahrenheit, Kelvin), pressure (Pascal, atm, bar, mmHg), concentration (mg/mL, μg/mL, % w/v, molarity), and time (seconds, minutes, hours).
Simple, fast, and always accessible without sign up or file size limits.
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Open Lab Calculator →More calculators are being added regularly. If there is a calculation you need that is not listed here, the Scitero team wants to hear from you.