Technical Resistor Calculator

Ohm's Law
Series/Parallel
Voltage Divider
RTD's
Wheatstone Bridge
RL, RC Filters

Ohm's Law

Enter Any Two Numbers Press Calculate to find the others.

Power (P)		Watts
Voltage (V)		Volts
Current (I)		Amps
Resistance (R)		Ohms

Ohm's Law
V=IR

Joule's Law
P=VI

Ohm's Law describes the relationships
between Voltage, Current, and Resistance
through a resistor. It is the most
fundamental equation in electronics.

Joule's Law describes the amount of
power that is required to sustain a
certain current through a circuit.

Using these two equations, if we know any two values, we can determine the others.

Series/Parallel

Enter Values Leave One Blank

RT

R1
R2
R3
R4

Find the equivalent resistance (RT)
of resistors in series, parallel, or a combination

Select Circuit Type

Series
Parallel
Triple Series
Triple Parallel
Series - Parallel
Series - Parallel - Parallel

If you get "No Solution" Result was a Negative Resistance.

Voltage Divider

RT - Total Ohms

Ohms

Voltage Dividers

Voltage Dividers are very useful for lowering voltages to use as inputs for control circuits. They are nice because the output voltages will track the input voltage very precisly.

The output voltages are determined by theratios of the resistors chosen.

Use this tab to find the best choice for your application. Fill in empty values, press Calculate.

Amps

Volts

Select Circuit

4 Resistors
3 Resistors
2 Resistors

RTD's

Temperature Coefficientof Resistance ( TCR )

Certain resistance material undergo a large
change in resistance due to temperature changes.
These changes are controllable and repeatable
making it highly suitable for measuring
temperatures. RTD's are a case of this.

TCR is measured in parts per million per C
(ppm/C), i.e. a 1 ohm resistor will change in
value by 0.0045 ohms for every 1C change in
temperature for a 4500ppm/C wire.

Use this tab to calculate either the resistance
change or temperature change based on different
standard resistance material.

Use the Temperature tab to convert Farenheit to
Centigrade. Temperatures must be in C.

Enter Starting Conditions	Enter One Ending Condition

Starting Temp ( C )	Ending Temp ( C )


Starting Resistance (Ohms)	Ending Resistance (Ohms)

Select TCR
( ppm/C )

+2600: 42% Ni Iron
+3850: Platinum
+3900: Copper
+4500: Balco
+5000: 99.5% Nickel
+6000: 99.9% Nickel

Temperature Conversion Enter Farenheit or Centigrade - click Convert		Farenheit ( F )		Centigrade ( C )
			To

Wheatstone Bridge

Volts

Ohms

R2		Ohms
R3		Ohms
R4		Ohms

Must choose R1, try 1000 Ohms to start
T0	C	Enter Temperature of 0 Volt Output
T1	C	Enter Temperature of Vout Output

Volts

Vout

Volts

Enter Range of Output, i.e. 1, for 0 - 1V output

	Select TCR ( ppm/C )
	+2600: 42% Ni Iron +3850: Platinum +3900: Copper +4500: Balco +5000: 99.5% Nickel +6000: 99.9% Nickel

Standard Circuit

RTD Circuit

RL, RC Filters

Select Circuit Type

Lowpass RL Circuit
Lowpass RC Circuit
Highpass RL Circuit
Highpass RC Circuit

Enter Any Two Numbers Press Calculate to find the others.

Frequency(F₀)		Hz
Inductance(L)		mH
Resistance(R)		Ohms

Technical Resistor Calculator

Ohm's Law

Series/Parallel

Voltage Divider

RTD's

Wheatstone Bridge

RL, RC Filters

Featured
Products

Riedon
Brochure

Technical
Calculator

Riedon
Guide to Resistors

Riedon
News

Technical Resistor Calculator

Ohm's Law

Series/Parallel

Voltage Divider

RTD's

Wheatstone Bridge

RL, RC Filters

Featured Products

Riedon Brochure

Technical Calculator

Riedon Guide to Resistors

Riedon News

Featured
Products

Riedon
Brochure

Technical
Calculator

Riedon
Guide to Resistors

Riedon
News