36 tools
Science
Astronomy, earth science, biology and the environment: distances between stars, earthquake energy, population growth and air quality.
Tools in this category
- ScienceEquivalent Exposure CalculatorChange the aperture or the ISO and get the shutter speed that keeps the exposure exactly the same, with the stops shown.
- ScienceEquivalent Focal Length CalculatorCrop factor, equivalent focal length, equivalent aperture and equivalent ISO for any sensor size.
- ScienceDistance Between Coordinates CalculatorGreat-circle distance between two points on Earth in kilometres, miles and nautical miles, with the initial bearing.
- ScienceAstrophotography Exposure CalculatorThe longest exposure before stars trail, by the 500 rule, the 600 rule and the NPF rule, with the trail length in pixels.
- ScienceDew Point CalculatorDew point from temperature and relative humidity, with the vapour pressure and absolute humidity.
- ScienceLight Travel Time CalculatorHow long light takes to cross a distance, in seconds, minutes, light years and astronomical units.
- ScienceHeat Index CalculatorApparent temperature in hot, humid weather, with how much above the real temperature it feels.
- ScienceReverberation Time CalculatorRT60 by Sabine and by Eyring, with the room volume, total absorption, Schroeder frequency and critical distance.
- ScienceDaylight Hours CalculatorLength of daylight at a latitude on a given day of the year, with the solar declination and noon sun height.
- ScienceRoom Modes CalculatorThe lowest standing-wave frequencies of a rectangular room, sorted, with each one marked axial, tangential or oblique.
- ScienceEarthquake Energy CalculatorEnergy released by an earthquake in joules and tonnes of TNT, and how it compares with another magnitude.
- ScienceTelescope Magnification CalculatorMagnification from an eyepiece, with the exit pupil, true field of view, useful maximum and limiting magnitude.
- ScienceAltitude Pressure CalculatorAir pressure, temperature, boiling point and oxygen partial pressure at altitude.
- ScienceDistance to the Horizon CalculatorHow far the horizon is from any height, with and without atmospheric refraction, and how far away a tall object stays visible.
- ScienceFlight Carbon Footprint CalculatorGreenhouse gas emissions of a flight per passenger, with and without the high-altitude multiplier.
- ScienceLight Meter CalculatorTurn a meter reading in cd/m² or lux into a shutter speed, for incident or reflected metering, using the ISO 2720 constants.
- ScienceMacro Magnification and Bellows CalculatorMagnification, bellows exposure factor, effective aperture and working distance from the focal length and the extension.
- SciencePopulation Growth CalculatorPopulation after a number of years at a continuous growth rate, with the doubling time.
- ScienceBacterial Growth CalculatorCell count after a period of exponential growth, the number of generations and the time to reach a million per millilitre.
- ScienceCrosswind Component CalculatorCrosswind and headwind components for a wind at an angle to the runway, with the margin to a stated limit.
- ScienceDiffraction Limit CalculatorAiry disk diameter, the f-number where diffraction reaches the pixel pitch, and whether it is visible yet.
- ScienceKepler's Third Law CalculatorOrbital period and speed of a body from its orbital radius and the mass it orbits.
- ScienceCircle of Confusion CalculatorThe circle of confusion for a sensor, by the diagonal rule or from the print size and how sharp you want the print to look.
- ScienceRocket Equation Calculator (Delta-v)Delta-v from specific impulse and the wet and dry masses of a stage, with mass ratio and propellant load.
- ScienceStar Luminosity CalculatorLuminosity of a star in solar units and watts, its peak colour, absolute magnitude and the flux reaching us.
- ScienceStar Magnitude CalculatorBrightness ratio between two magnitudes, and the absolute magnitude of a star at a given distance.
- ScienceEarthquake Epicentre Distance CalculatorDistance to an earthquake from the delay between the P and S waves on a seismogram.
- ScienceReciprocity Failure CalculatorThe corrected exposure time for film at long exposures, by the Schwarzschild law, including any filter stops.
- ScienceSchwarzschild Radius CalculatorThe event horizon radius for a given mass, in metres and kilometres, with the mean density inside it.
- ScienceHohmann Transfer CalculatorThe two burns, total delta-v and travel time to move between two circular orbits.
- ScienceHardy-Weinberg Carrier Frequency CalculatorAllele frequencies, carrier frequency and genotype proportions from the frequency of the recessive phenotype.
- ScienceMichaelis-Menten Enzyme Kinetics CalculatorReaction rate, fraction of Vmax and catalytic efficiency from Vmax, Km and substrate concentration.
- ScienceAstronomical Distance ConverterConvert astronomical units, light-years, parsecs, kilometres and solar radii.
- ScienceRadiation Dose Converter (Sievert and Rem)Convert sievert, millisievert, microsievert, rem and millirem.
- ScienceRadioactivity ConverterConvert becquerel, curie, disintegrations per minute and rutherford.
- ScienceAbsorbed Dose Converter (Gray and Rad)Convert gray, milligray, kilogray, rad and erg per gram.