Physics and Chemistry Calculators
These calculators handle the core formulas of introductory physics and chemistry. On the mechanics side, work out kinetic and potential energy, the range and height of a projectile, how long a fall takes with or without air resistance, and the forces in F = ma, weight and friction on a slope. For matter and waves, find density and identify a material, convert wavelength to frequency and photon energy, and solve the ideal gas law. For solution chemistry, the pH calculator covers strong and weak acids and bases, polyprotic acids and buffers.
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All Physics & Chemistry (8)
Kinetic Energy Calculator
Kinetic and potential energy, solving for mass or velocityProjectile Motion Calculator
Range, max height and flight time, with the trajectory plottedFree Fall Calculator
Fall time, impact speed and distance, with or without dragForce Calculator
Newton’s second law, weight and friction forceDensity Calculator
Density, mass or volume, with a material density tableWavelength & Frequency Calculator
Wavelength, frequency, period and photon energy for light and soundIdeal Gas Law Calculator
Solve PV = nRT for any variable in any unitspH Calculator
pH, pOH and ions for strong and weak acids, bases and buffers
Which tool do I need?
Find how far and how high a thrown ball goes
Enter the launch speed, angle and height to get the range, peak height, flight time and the best launch angle.
Work out how long a fall takes
Enter the drop height, switch on air resistance if you want, and get the fall time, impact speed and terminal velocity.
Check whether a box will slide down a ramp
Pick the surfaces and slope angle to get friction, the angle of repose and the force needed to move it.
Identify a metal or test a gold item
Weigh it in air and in water, or enter mass and volume, to get the density and the closest material.
Convert a laser or radio wavelength
Enter a wavelength, frequency or photon energy to get the others, the spectrum band and the colour.
Find the pH of an acid, base or buffer
Choose the substance and concentration, or the acid and base amounts of a buffer, and get pH, pOH and ion concentrations.
About Physics & Chemistry
Every tool uses the exact SI defining constants (the speed of light, Planck, Boltzmann and Avogadro constants and the elementary charge) and standard gravity of 9.80665 m/s², accepts metric and US units, and shows the formula behind each answer. Where a quick textbook shortcut exists, such as the square-root rule for a weak acid or Henderson-Hasselbalch for a buffer, the calculator also solves the problem exactly and shows how far apart the two answers are.
Results are for learning, checking homework and lab preparation. Real objects meet air resistance, real gases depart from ideal behaviour at high pressure, and real solutions have activity effects, so each calculator notes the limits of its model. Everything runs in your browser.
Guides
- Projectile Motion Equations: Range, Height, Time and the Best AngleSplit the launch into horizontal and vertical motion and every projectile question becomes two simple equations. Range, peak height, flight time, launching from a height and hitting a target.
- Free Fall With and Without Air Resistance: Fall Time and Terminal VelocityThe vacuum formulas, what drag does to them, how terminal velocity depends on mass, area and air density, and the exact tanh solution for a falling object, with worked numbers.
- The Ideal Gas Law PV = nRT: Units, STP and When It FailsWhere PV = nRT comes from, the exact value of R, which units to use, absolute versus gauge pressure, molar volume at different STPs, gas density, the combined gas law and real-gas limits.
- How to Calculate pH: Strong and Weak Acids, Bases and BufferspH from concentration for strong and weak acids and bases, polyprotic acids, the Henderson-Hasselbalch equation, why 10⁻⁸ M HCl is not pH 8, and how temperature moves neutral pH.
Frequently asked questions
Which physical constants do these calculators use?
The exact values from the 2019 SI: c = 299,792,458 m/s, h = 6.62607015 × 10⁻³⁴ J·s, e = 1.602176634 × 10⁻¹⁹ C, NA = 6.02214076 × 10²³ per mol and k = 1.380649 × 10⁻²³ J/K, so R = 8.314462618 J/(mol·K). Standard gravity is 9.80665 m/s².
Do the motion calculators include air resistance?
The free fall calculator can model quadratic air drag with terminal velocity. The projectile calculator assumes no air resistance, which is close for slow, heavy objects and an upper bound for fast, light ones.
Can I mix metric and US units?
Yes. Each field has its own unit picker, so you can enter a mass in pounds, a speed in km/h and read the energy in joules or foot-pounds. Conversions use the exact definitions of the pound, foot and gallon.
How accurate are the pH results?
The pH calculator solves the full charge balance including water, so it is exact for the ideal-solution model. Real solutions above about 0.1 M differ by a few hundredths to a tenth of a pH unit because of activity effects.
When does the ideal gas law give wrong answers?
At high pressures, low temperatures and near condensation. Air at room temperature is within about 1% up to several bar, but steam, CO₂ and propane near their saturation conditions can be far off.