{"success":true,"version":"v1","request":{"tool":"list_calculators","category":"science"},"result":{"entity_type":"calculator_list","status":"completed","count":14,"calculators":[{"calculator_id":"punnett-square","entity_type":"calculator","name":"Punnett Square Calculator","category":"science","tool_name":"calculate_punnett_square","description":"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.","use_when":"You need the expected offspring ratios (e.g. 3 : 1 or 9 : 3 : 3 : 1), genotype probabilities or the full grid for a Mendelian cross written with allele letters such as Aa × Aa or AaBb × AaBb.","do_not_use_when":"Genes are linked, sex-linked, codominant or incompletely dominant, polygenic or have more than two alleles, or you need allele frequencies in a population (use 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equilibrium.","do_not_use_when":"The locus has more than two alleles or is X-linked, you only know phenotype counts of a dominant trait (then q = √(recessive fraction) is the only estimate and no test is possible), or you need a general contingency-table test (use chi-square-test).","required_inputs":["count_homozygous_dominant","count_heterozygous","count_homozygous_recessive"],"optional_inputs":[],"urls":{"html":"https://tttkmbb.com/science/hardy-weinberg","markdown":"https://tttkmbb.com/science/hardy-weinberg.md","schema":"https://tttkmbb.com/api/v1/calculators/hardy-weinberg","api":"https://tttkmbb.com/api/v1/calculate/hardy-weinberg"}},{"calculator_id":"population-growth","entity_type":"calculator","name":"Population Growth Calculator","category":"science","tool_name":"calculate_population_growth","description":"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 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half-life).","required_inputs":[],"optional_inputs":["percent_c14_remaining","age_years","half_life_years"],"urls":{"html":"https://tttkmbb.com/science/carbon-dating","markdown":"https://tttkmbb.com/science/carbon-dating.md","schema":"https://tttkmbb.com/api/v1/calculators/carbon-dating","api":"https://tttkmbb.com/api/v1/calculate/carbon-dating"}},{"calculator_id":"earthquake-magnitude","entity_type":"calculator","name":"Earthquake Magnitude Energy Calculator","category":"science","tool_name":"compare_earthquake_magnitudes","description":"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.","use_when":"You want to know how much energy an earthquake of a given magnitude releases, how many times stronger one magnitude is than another, or which descriptive class (minor, moderate, major, great) a magnitude belongs to.","do_not_use_when":"You need shaking intensity or damage at a location (Modified Mercalli intensity depends on distance, depth and soil), or magnitudes on other scales without conversion to moment magnitude.","required_inputs":["magnitude"],"optional_inputs":["compare_magnitude"],"urls":{"html":"https://tttkmbb.com/science/earthquake-magnitude","markdown":"https://tttkmbb.com/science/earthquake-magnitude.md","schema":"https://tttkmbb.com/api/v1/calculators/earthquake-magnitude","api":"https://tttkmbb.com/api/v1/calculate/earthquake-magnitude"}},{"calculator_id":"planet-weight","entity_type":"calculator","name":"Weight on Other Planets Calculator","category":"science","tool_name":"calculate_weight_on_planets","description":"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 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law T = 2π√(a³/GM), plus the circular orbital speed √(GM/a), for the Sun, Earth, Moon, Mars, Jupiter or a custom mass.","use_when":"You need the period or speed of a satellite, moon or planet from its orbit size (e.g. the ISS at 6,791 km from Earth's centre, or 1 AU around the Sun).","do_not_use_when":"You need the speed to leave a body (use escape-velocity), a transfer orbit or the position along an elliptical orbit at a given time, or relativistic corrections.","required_inputs":["semi_major_axis"],"optional_inputs":["axis_unit","central_body","central_mass_kg"],"urls":{"html":"https://tttkmbb.com/science/orbital-period","markdown":"https://tttkmbb.com/science/orbital-period.md","schema":"https://tttkmbb.com/api/v1/calculators/orbital-period","api":"https://tttkmbb.com/api/v1/calculate/orbital-period"}},{"calculator_id":"escape-velocity","entity_type":"calculator","name":"Escape Velocity Calculator","category":"science","tool_name":"calculate_escape_velocity","description":"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.","use_when":"You need the speed required to escape a planet or moon without further propulsion, the speed of a low circular orbit, or the surface gravity of a body from its mass and radius.","do_not_use_when":"You need the period of an orbit of a given size (use orbital-period), the rocket delta-v including gravity and drag losses, or the weight of an object on a planet (use planet-weight).","required_inputs":["body"],"optional_inputs":["mass_kg","radius_m","altitude_m"],"urls":{"html":"https://tttkmbb.com/science/escape-velocity","markdown":"https://tttkmbb.com/science/escape-velocity.md","schema":"https://tttkmbb.com/api/v1/calculators/escape-velocity","api":"https://tttkmbb.com/api/v1/calculate/escape-velocity"}},{"calculator_id":"centrifuge-rcf-rpm","entity_type":"calculator","name":"Centrifuge RCF / RPM Converter","category":"science","tool_name":"convert_centrifuge_rcf_rpm","description":"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.","use_when":"A protocol specifies a centrifugation force in ×g and you need the rpm for your rotor, or you know the rpm and radius and need the force applied to the sample.","do_not_use_when":"You need the centripetal force in newtons on a specific mass (use centripetal-force), or sedimentation times and k-factors of ultracentrifuge rotors.","required_inputs":["radius_cm"],"optional_inputs":["rpm","rcf_g"],"urls":{"html":"https://tttkmbb.com/science/centrifuge-rcf-rpm","markdown":"https://tttkmbb.com/science/centrifuge-rcf-rpm.md","schema":"https://tttkmbb.com/api/v1/calculators/centrifuge-rcf-rpm","api":"https://tttkmbb.com/api/v1/calculate/centrifuge-rcf-rpm"}},{"calculator_id":"hemocytometer-count","entity_type":"calculator","name":"Hemocytometer Cell Count Calculator","category":"science","tool_name":"calculate_hemocytometer_cell_count","description":"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.","use_when":"You counted cells in the large 1 mm² squares of a Neubauer hemocytometer and need the concentration, the number of cells in your flask or the volume to seed a given number of cells.","do_not_use_when":"You counted in the small central squares or used a different chamber depth (adjust the volume per square), used an automated counter, or need cell growth rates (use cell-doubling-time).","required_inputs":["cells_counted"],"optional_inputs":["squares_counted","dilution_factor","sample_volume_ml","dead_cells_counted","target_cells"],"urls":{"html":"https://tttkmbb.com/science/hemocytometer-count","markdown":"https://tttkmbb.com/science/hemocytometer-count.md","schema":"https://tttkmbb.com/api/v1/calculators/hemocytometer-count","api":"https://tttkmbb.com/api/v1/calculate/hemocytometer-count"}},{"calculator_id":"cell-doubling-time","entity_type":"calculator","name":"Cell Doubling Time Calculator","category":"science","tool_name":"calculate_cell_doubling_time","description":"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.","use_when":"You have cell counts at two time points (e.g. seeding and harvest) and need the doubling time, the number of population doublings, or the expected count after a further period.","do_not_use_when":"The culture has left exponential growth (lag or plateau phase), the final count is not larger than the initial one, or you want to project a population with a known rate (use population-growth).","required_inputs":["initial_count","final_count","elapsed_hours"],"optional_inputs":["project_hours"],"urls":{"html":"https://tttkmbb.com/science/cell-doubling-time","markdown":"https://tttkmbb.com/science/cell-doubling-time.md","schema":"https://tttkmbb.com/api/v1/calculators/cell-doubling-time","api":"https://tttkmbb.com/api/v1/calculate/cell-doubling-time"}},{"calculator_id":"michaelis-menten","entity_type":"calculator","name":"Michaelis-Menten Enzyme 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salt- and concentration-corrected nearest-neighbour Tm values (as used by commercial primer tools), degenerate primers beyond N, or modified bases.","required_inputs":["sequence"],"optional_inputs":[],"urls":{"html":"https://tttkmbb.com/science/pcr-primer-tm","markdown":"https://tttkmbb.com/science/pcr-primer-tm.md","schema":"https://tttkmbb.com/api/v1/calculators/pcr-primer-tm","api":"https://tttkmbb.com/api/v1/calculate/pcr-primer-tm"}},{"calculator_id":"dna-concentration","entity_type":"calculator","name":"DNA / RNA Concentration Calculator","category":"science","tool_name":"calculate_nucleic_acid_concentration","description":"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.","use_when":"You measured A260 (and optionally A280, A230) on a spectrophotometer or NanoDrop and need the concentration in µg/mL or ng/µL, the total amount in a sample, or a purity check.","do_not_use_when":"The sample is very dilute or contaminated (fluorometric assays such as PicoGreen are more specific), you need the molar concentration of a specific oligo (requires its extinction coefficient), or the reading is outside the instrument's linear range.","required_inputs":["a260"],"optional_inputs":["dilution_factor","nucleic_acid","a280","a230","sample_volume_ul"],"urls":{"html":"https://tttkmbb.com/science/dna-concentration","markdown":"https://tttkmbb.com/science/dna-concentration.md","schema":"https://tttkmbb.com/api/v1/calculators/dna-concentration","api":"https://tttkmbb.com/api/v1/calculate/dna-concentration"}}]},"timestamp":"2026-09-24T03:46:42Z","next_actions":[],"links":{"docs":"https://tttkmbb.com/calculators.md"}}