Engineering
Engineering calculations connect a small set of relationships: voltage and current, address space, motion, electrical power and solution concentration. Each calculator here solves one standard relationship so you can check a hand calculation or size a component before building anything.
The category spans electrical, networking, mechanical and chemical work; choose the domain that matches your problem.
Browse engineering calculators
Networking
Motion
Chemistry
Which engineering calculator do you need?
Relate voltage, current and resistance in a DC circuit, and check power dissipation from the same values.
Plan an IPv4 network: network and broadcast addresses, usable host range and mask from a CIDR prefix.
Find average speed from a distance and a time, or the time a trip will take at a known speed.
Prepare a solution of a target molar concentration from mass, molar mass and volume.
DC relationships
Ohm's law links voltage, current and resistance (V = I × R), and power links voltage and current (P = V × I). Identify which two quantities you actually know — measured values usually beat assumed ones — then derive the rest and sanity-check the magnitude.
Watch prefixes: milliamps, kilohms and kilowatts are common in real circuits, and entering 20 mA as 20 A changes the result by a factor of a thousand.
Networks, motion and concentration
Subnetting is binary arithmetic in disguise: the prefix length decides how many bits address the network and how many remain for hosts. The broadcast and network addresses are not assignable, which is why usable hosts are two fewer than the address count.
Velocity is distance divided by time and is a scalar; average speed over a trip hides changes along the way. Molarity is moles per litre, so it depends on getting molar mass and volume units right.
Where ideal formulas stop
- Real components have tolerances, temperature drift and non-linear behaviour that ideal formulas ignore.
- Subnet results assume classless IPv4 and do not model routing policy, reservations or VLAN design.
- Chemical and motion calculations assume ideal conditions — purity, temperature and friction can shift real results.