Biology Calculators
Last updated: September 2026
DNA Concentration Calculator
Estimate double-stranded DNA concentration from absorbance at 260 nm using the standard 50 μg/ml per A260 conversion.
Metabolic Rate Calculator
Calculate mass-specific metabolic rate from an organism's oxygen consumption, body mass, and respiratory quotient.
Photosynthetic Rate Calculator
Calculate the total CO₂ a leaf fixes over a measurement period from its net assimilation rate (μmol/m²/s), leaf area and time.
Enzyme Activity Calculator
Compute enzyme activity in U/mL from the rate of absorbance change in a spectrophotometric assay using the Beer-Lambert law.
Protein Concentration Calculator
Compute protein concentration from absorbance at 595 nm using a linear standard curve.
PCR Efficiency Calculator
Compute the amplification efficiency of a qPCR reaction from the slope of a standard curve fitting Cq values against the log of template concentration.
PCR Primer Tm Calculator
Calculates the melting temperature (Tm) of short PCR primers using the Wallace rule base-counting method.
Protein Extinction Coefficient Calculator
Estimates a protein's molar extinction coefficient at 280 nm from its tryptophan, tyrosine, and cysteine residue counts.
Cell Density Calculator
Estimate cell concentration in cells/mL from a haemocytometer count using cellCount, the number of squares counted, and the dilution factor.
Gene Expression Fold Change Calculator
Determine how much a gene is up- or down-regulated by dividing treatment expression by control expression.
Allele Frequency Calculator
Compute the frequency of a specific allele in a population from counts of each genotype (AA, Aa, aa).
Chlorophyll Concentration Calculator
Converts spectrophotometer absorbance readings at 645 nm and 663 nm into total chlorophyll concentration in a plant extract.
Chromosome Map Distance Calculator
Convert recombination frequency into genetic map distance in centimorgans (cM) between two loci on a chromosome.
Cell Surface Area to Volume Ratio Calculator
Calculate the surface area to volume ratio (SA:V) of a spherical cell given its radius.
Cardiac Output Calculator
Calculates cardiac output in liters per minute from heart rate (bpm) and stroke volume (mL).