Science CalculatorsFree Chemistry, Physics, Biology and Earth Science Tools
42 step-by-step calculators for students, teachers, lab staff and curious minds. Pick a tile, enter your values, and see the formula, the units and the worked answer.
What are science calculators? Science calculators are formula-specific tools that solve one scientific relationship at a time, such as molarity (M = n/V), Ohm’s law (V = IR) or half-life decay, and show every step with correct units and significant figures. Unlike a general scientific calculator, each one knows the equation, the constants and the unit conversions for you.
Constants follow NIST CODATA values, units follow the NIST SI Guide, and atomic weights follow IUPAC.
By Manzoor Ahmad, web development expert · Updated
Showing all 42 science calculators
Chemistry Calculators
Solution prep, stoichiometry, gas laws, acids and bases. The tools a general chemistry course and a working lab bench lean on every day.
See all chemistry calculators →
Molar Mass Calculator
Molecular weight of any compound from its chemical formula, element by element.
M = Σ(n × A)Open calculator →
02PopularMMolarity Calculator
Concentration, mass needed or volume of a solution in mol/L.
M = n ÷ VOpen calculator →
03DlDilution Calculator
How much stock solution to dilute to hit a target concentration.
C₁V₁ = C₂V₂Open calculator →
04GmGrams to Moles Calculator
Convert mass to moles (and back) for any element or compound.
n = m ÷ MOpen calculator →
05MoMolality Calculator
Moles of solute per kilogram of solvent, used for boiling and freezing point work.
b = n ÷ kg solventOpen calculator →
06PcPercent Composition Calculator
Mass percent of each element in a compound.
% = (mₑ ÷ M) × 100Open calculator →
07EfEmpirical Formula Calculator
Simplest whole-number formula from percent or mass data.
mol ratio ÷ smallestOpen calculator →
08LrLimiting Reactant Calculator
Find which reagent runs out first and how much excess remains.
min(nᵢ ÷ coefᵢ)Open calculator →
09TyTheoretical Yield Calculator
Maximum product mass a reaction can produce from the limiting reactant.
n_lim × ratio × MOpen calculator →
10PyPercent Yield Calculator
How efficient your reaction was, actual versus theoretical.
(actual ÷ theo) × 100Open calculator →
11GsIdeal Gas Law Calculator
Solve for pressure, volume, moles or temperature of a gas.
PV = nRTOpen calculator →
12CgCombined Gas Law Calculator
Boyle’s, Charles’s and Gay-Lussac’s laws in one tool.
P₁V₁/T₁ = P₂V₂/T₂Open calculator →
13pHpH Calculator
pH, pOH, [H⁺] and [OH⁻] for strong and weak acids and bases.
pH = −log[H⁺]Open calculator →
14HhHenderson–Hasselbalch Calculator
Buffer pH and the acid-to-base ratio you need to hit it.
pH = pKa + log(A⁻/HA)Open calculator →
15Populart½Half-Life Calculator
Amount remaining, elapsed time or half-life for radioactive and drug decay.
N = N₀(½)^(t/t½)Open calculator →
16PopularSfSignificant Figures Calculator
Count sig figs, round correctly and do sig-fig arithmetic.
count · round · operateOpen calculator →
Physics Calculators
Motion, forces, energy, waves, heat and circuits, from first-year mechanics to the electronics workbench.
See all physics calculators →
Kinetic Energy Calculator
Energy of a moving object, or the speed or mass behind it.
KE = ½mv²Open calculator →
18PEPotential Energy Calculator
Gravitational potential energy from mass and height.
PE = mghOpen calculator →
19FForce Calculator
Newton’s second law for force, mass or acceleration.
F = maOpen calculator →
20aAcceleration Calculator
Rate of change of velocity from speeds, time or distance.
a = Δv ÷ ΔtOpen calculator →
21vFinal Velocity Calculator
Final speed from initial velocity, acceleration and time or distance.
v = u + atOpen calculator →
22pMomentum Calculator
Linear momentum and impulse for collisions and pushes.
p = mvOpen calculator →
23FfFree Fall Calculator
Fall time, impact speed and drop height without air resistance.
h = ½gt²Open calculator →
24PmProjectile Motion Calculator
Range, maximum height and flight time from launch speed and angle.
R = v²·sin2θ ÷ gOpen calculator →
25FcCentripetal Force Calculator
Force needed to keep an object moving in a circle.
F = mv² ÷ rOpen calculator →
26PopularΩOhm’s Law Calculator
Voltage, current, resistance and power from any two known values.
V = IROpen calculator →
27λWavelength Calculator
Convert frequency to wavelength for light, sound and radio waves.
λ = v ÷ fOpen calculator →
28ρDensity Calculator
Density, mass or volume with automatic unit conversion.
ρ = m ÷ VOpen calculator →
29cSpecific Heat Calculator
Heat absorbed or released, or the specific heat of a material.
Q = mcΔTOpen calculator →
30vₑEscape Velocity Calculator
Speed needed to escape a planet’s or moon’s gravity.
vₑ = √(2GM ÷ r)Open calculator →
Biology Calculators
Genetics, population genetics and the dilution and growth math used in microbiology and cell culture.
Punnett Square Calculator
Monohybrid and dihybrid crosses with genotype and phenotype ratios.
Aa × Aa → 1:2:1Open calculator →
32HwHardy–Weinberg Calculator
Allele and genotype frequencies, including carrier rates.
p² + 2pq + q² = 1Open calculator →
33SdSerial Dilution Calculator
Step-by-step dilution series, total dilution factor and CFU/mL.
DF = (Vs + Vd) ÷ VsOpen calculator →
34TdDoubling Time Calculator
Cell or bacterial doubling time and growth rate from two counts.
Td = t·ln2 ÷ ln(N/N₀)Open calculator →
Earth and Space Science Calculators
Weather and humidity, radiometric dating and astronomy, built on NOAA, National Weather Service and NASA reference data.
Dew Point Calculator
Dew point from air temperature and relative humidity.
Magnus formulaOpen calculator →
36RHRelative Humidity Calculator
Relative humidity from temperature and dew point.
RH = e ÷ eₛ × 100Open calculator →
37HIHeat Index Calculator
“Feels like” temperature with NWS danger categories.
NWS RothfuszOpen calculator →
38WCWind Chill Calculator
Cold “feels like” temperature and frostbite time.
NWS 2001 formulaOpen calculator →
39PopularWWeight on Other Planets Calculator
Your weight on the Moon, Mars, Jupiter and every planet.
W = m × g_planetOpen calculator →
40¹⁴CCarbon Dating Calculator
Age of a sample from its remaining carbon-14.
t = −8267 · ln(N/N₀)Open calculator →
41lyLight Year Calculator
Convert light-years to km, miles, AU and parsecs, plus travel time.
1 ly ≈ 9.4607×10¹⁵ mOpen calculator →
42LdLightning Distance Calculator
How far away a storm is from the flash-to-thunder delay.
d = 343 m/s × tOpen calculator →
No calculator matches that search yet. Try a formula symbol (like “PV” or “C1V1”) or a broader word like “energy”.
Which Science Calculator Do I Need?
Most homework and lab questions start with “I know this, I need that.” Match what you have to what you want and the right tool falls out.
| You know… | You want… | Use this calculator |
|---|---|---|
| Mass of solute and solution volume | Concentration in mol/L | Molarity Calculator |
| Stock concentration and target concentration | Volume of stock to measure | Dilution Calculator |
| Masses of two reactants | Maximum product possible | Limiting Reactant, then Theoretical Yield |
| Starting amount and half-life | Amount left after time t | Half-Life Calculator |
| Voltage and resistance | Current and power | Ohm’s Law Calculator |
| Launch speed and angle | Range and peak height | Projectile Motion Calculator |
| Two parents’ genotypes | Offspring probabilities | Punnett Square Calculator |
| Temperature and humidity | Condensation point or “feels like” | Dew Point or Heat Index |
Worked Example: A Real Dilution, Step by Step
Dilution is one of the most common lab calculations, and it shows why a formula-specific calculator beats doing it in your head. Suppose you need 250 mL of 0.9% sodium chloride and the stock on hand is a 23.4% concentrate.
Notice two things the calculator handles for you. First, both concentrations must be in the same unit (here, % w/v), otherwise the answer is off by orders of magnitude. Second, the inputs carry two to three significant figures, so the honest answer is 9.6 mL, not 9.6153846 mL.
Teaching example only. Real compounding follows your facility’s protocols, verified references and a second check. A calculator supports your judgment, it never replaces it.
Physical Constants Used Across These Calculators
Every DexoCalc science tool draws from the same constant set, so an answer from the Ideal Gas Law Calculator agrees with one from the Molarity Calculator to the last digit. Since the 2019 SI redefinition, several of these constants are exact by definition.
| Constant | Symbol | Value (SI) | Used in |
|---|---|---|---|
| Avogadro constant | Nₐ | 6.02214076 × 10²³ mol⁻¹ (exact) | Molar mass, grams to moles |
| Molar gas constant | R | 8.314462618… J·mol⁻¹·K⁻¹ (exact) | Ideal gas law, combined gas law |
| Speed of light in vacuum | c | 299 792 458 m·s⁻¹ (exact) | Wavelength, light year |
| Planck constant | h | 6.62607015 × 10⁻³⁴ J·s (exact) | Photon energy (wavelength tool) |
| Standard gravity | g₀ | 9.80665 m·s⁻² (exact, conventional) | Free fall, potential energy, projectile |
| Newtonian gravitational constant | G | 6.67430 × 10⁻¹¹ m³·kg⁻¹·s⁻² | Escape velocity, planetary weight |
| Elementary charge | e | 1.602176634 × 10⁻¹⁹ C (exact) | Electricity and circuit tools |
| Carbon-14 half-life (Cambridge) | t½ | 5,730 ± 40 years | Carbon dating |
How We Build and Check Every Science Calculator
A science calculator is only useful if you can trust the last digit. Each tool in this hub goes through the same process before it is published:
- One formula, stated openly. The governing equation, every variable and its SI unit are printed on the page, not hidden in code.
- Reference constants only. Values come from NIST CODATA, IUPAC standard atomic weights and NOAA or NWS formulas, never rounded “textbook” shortcuts.
- Unit conversion before math. Inputs in mL, °F, psi or g are converted to SI first, which removes the most common student error.
- Significant figures respected. Results are rounded to match your input precision, with the full-precision value available for checking.
- Tested against published problems. Each calculator is run against worked examples from open textbooks such as OpenStax Chemistry and University Physics before release.
Study path: where to start
New to chemistry? Work through significant figures, then molar mass, grams to moles and molarity, in that order, because each one feeds the next. For physics, start with acceleration and force before moving to energy and projectile motion.
Science Calculators: Frequently Asked Questions
A scientific calculator is a general device with functions like log, sin and exponents. A science calculator here is a formula-specific tool: it already knows the equation (for example PV = nRT), the constants and the unit conversions, and it shows each solving step.
Yes. All 42 calculators are free, run in your browser and need no account or download. Nothing you type is stored.
They are ideal for checking homework and learning the method, since every result shows the formula and steps. For graded exams, follow your instructor’s rules; most expect you to show the working yourself.
Calculations use NIST CODATA constants and IUPAC atomic weights at full double precision, then round to your input’s significant figures. Accuracy is limited by your inputs and by model assumptions, such as ideal-gas behavior or no air resistance.
It uses R = 8.314462618 J·mol⁻¹·K⁻¹, and switches automatically to 0.082057 L·atm·mol⁻¹·K⁻¹ or 62.364 L·Torr·mol⁻¹·K⁻¹ to match the pressure and volume units you choose.
Results are rounded to the correct number of significant figures, so the answer never claims more precision than your measurements. The full unrounded value is shown alongside for checking.
Yes, for first-order elimination it estimates how much of a drug remains after a given time. It is an educational estimate; actual dosing decisions belong to the prescriber and pharmacist, who consider kidney function, liver function and interactions.
Yes. Every tool is built mobile-first, with full-width inputs, large tap targets and tables that reflow into cards on small screens.
Each calculator accepts common SI and US customary units (for example g, kg, lb; mL, L; °C, °F, K; atm, kPa, psi, Torr) and converts them to SI before solving.
They are built by Manzoor Ahmad, a web development expert with 13 years of experience, and checked against published textbook problems and reference data before publication.
Sources and References
- NIST Reference on Constants, Units and Uncertainty (CODATA)
- NIST Special Publication 811: Guide for the Use of the International System of Units
- IUPAC Commission on Isotopic Abundances and Atomic Weights: Standard Atomic Weights
- NOAA Weather Prediction Center: The Heat Index Equation
- National Weather Service: Wind Chill Chart
- NASA Planetary Fact Sheet
- OpenStax Chemistry 2e and University Physics Volume 1
Disclaimer: DexoCalc science calculators are educational tools. Results depend on your inputs and the stated model assumptions. Verify critical laboratory, clinical, engineering or safety calculations with qualified professionals and official references.