Biology, Earth & Space calculators (14)

Punnett squares, Hardy-Weinberg, population growth, carbon dating, earthquake magnitude and energy, weight on other planets, orbital period, escape velocity, centrifuge RCF, cell counting and doubling time, enzyme kinetics, PCR primer Tm, DNA concentration.

Markdown version: /science.md · JSON: /api/v1/calculators?category=science

• Punnett Square Calculator — Builds the Punnett square for a one-gene (monohybrid) or two-gene (dihybrid) cross from the parents' genotypes and reports the offspring genotype and phenotype ratios, assuming complete dominance and independent assortment. (md · api)
• Hardy-Weinberg Equilibrium Calculator — Estimates the allele frequencies p and q of a two-allele locus from observed genotype counts, computes the genotype counts expected under Hardy–Weinberg equilibrium (p², 2pq, q²) and tests the deviation with a chi-square goodness-of-fit test with 1 degree of freedom. (md · api)
• Population Growth Calculator — Projects a population over a number of periods with discrete exponential growth P0(1 + r)^t, continuous exponential growth P0·e^(rt) or the logistic model with a carrying capacity K, and reports the final size, growth multiple, doubling time and a period-by-period schedule. (md · api)
• Carbon Dating Calculator — Computes the age of a sample from the percentage of carbon-14 remaining by first-order decay with the Cambridge half-life of 5730 years, or the remaining percentage from a known age, and also reports the conventional radiocarbon age based on the Libby half-life of 5568 years. (md · api)
• Earthquake Magnitude Energy Calculator — Converts a moment magnitude into radiated seismic energy with the Gutenberg–Richter relation log10 E = 1.5 M + 4.8, expresses it in tons of TNT and Hiroshima-bomb equivalents, classifies the magnitude with the USGS classes and compares two magnitudes by wave amplitude and energy. (md · api)
• Weight on Other Planets Calculator — Converts a mass (the scale reading on Earth) into the weight in newtons and the equivalent scale reading on Mercury, Venus, Earth, the Moon, Mars, Jupiter, Saturn, Uranus, Neptune, Pluto and the Sun, using surface gravity values from the NASA planetary fact sheets. (md · api)
• Orbital Period Calculator — Computes the orbital period from the semi-major axis and the central body's gravitational parameter GM with Kepler's third law T = 2π√(a³/GM), plus the circular orbital speed √(GM/a), for the Sun, Earth, Moon, Mars, Jupiter or a custom mass. (md · api)
• Escape Velocity Calculator — Computes the escape velocity √(2GM/r) and the circular orbital velocity √(GM/r) at the surface (or a given altitude) of Earth, the Moon, Mars, Jupiter, the Sun or a custom body defined by mass and radius, plus its surface gravity GM/R². (md · api)
• Centrifuge RCF / RPM Converter — Converts between rotor speed (rpm) and relative centrifugal force (RCF, in multiples of g) for a given rotor radius with RCF = 1.118 × 10⁻⁵ × r_cm × rpm², solving whichever of the two is not given. (md · api)
• Hemocytometer Cell Count Calculator — Converts a hemocytometer count into cell concentration with cells/mL = (cells counted ÷ large squares counted) × dilution factor × 10⁴, and optionally the total cells in a sample, trypan-blue viability and the volume that contains a target number of cells. (md · api)
• Cell Doubling Time Calculator — Computes the doubling time of an exponentially growing cell culture (or any population) from an initial count, a final count and the elapsed time with Td = t × ln 2 / ln(Nf / N0), plus the number of doublings, the specific growth rate and an optional projected count. (md · api)
• Michaelis-Menten Enzyme Kinetics Calculator — Computes the initial reaction velocity of an enzyme with Michaelis–Menten kinetics, v = Vmax × [S] / (Km + [S]), the fraction of Vmax reached, the substrate concentrations for 50 % and 90 % of Vmax, and optionally a rate table for a list of substrate concentrations. (md · api)
• PCR Primer Tm Calculator — Analyses a DNA primer sequence: length, GC content, melting temperature by the Wallace rule 2(A+T) + 4(G+C) and by the basic GC formula 64.9 + 41 × (G+C − 16.4) / N, single-stranded molecular weight, complement, reverse complement, self-complementarity and simple design checks. (md · api)
• DNA / RNA Concentration Calculator — Converts an absorbance reading at 260 nm into nucleic acid concentration with the standard factors (dsDNA 50, ssDNA 33, RNA 40, oligonucleotide 33 µg/mL per A260 unit) and a dilution factor, and assesses purity from the A260/A280 and A260/A230 ratios. (md · api)