LED Series Resistor Calculator

Use the calculator below to determine the series resistor needed to connect various series combinations of light emitting diodes or "LEDs". Use a resistor rated higher than the displayed power in the box below "Power (W)".

Formula: R = (Vs - Vf) / If

 

(Supply Voltage Vs   Forward Voltage Vf)   Forward Current If (mA)
÷
         
Calculate        
         
Resistor Value Ω   Power (W)    
     
         
Reset        
         

Calculator: Flow through circular Orifice.

Plot: Flow Rate v Orifice (for two pressure drops)
Plot: Pressure drop over Orifice vs Flow Rate (for two Orifice diameters)

Calculator: Flow through an Orifice.
The calculator determine the requried velocity throguh a pipe to achive a desire flow rate.

Fluid Velocity Calculator

The Hazen-Williams method is valid for water flowing at ordinary temperatures of 4 to 25 oC through pressurized pipes.

Major Loss Hazen Calculator

The Darcy-Weisbach method is generally considered more accurate than the Hazen-Williams method. Additionally, the Darcy-Weisbach method is valid for any liquid or gas. Major Loss Darcy-Colbrook Calculator
The Darcy-Weisbach method is generally considered more accurate than the Hazen-Williams method. This calculator uses the Swamee Jain apprximation for the friction factor. Major Loss Darcy-Swamee Calculator
This calculator compares methods for calculating head loss in pressure pipes.

Head Loss Comparision Calculator

This calculator will the flow through an Orifice and the pressure drop. Used for flow measurement and also to discharge water at a known rate.

Orifice Flow Calculator

This calculator This calculator will calculate the force applied by the ballscrew as a result of an applied torque.

Lead Screw Force Calculator

Convert Bin to Hex and Hex to Bin

Bin to Hex Conversion

This calculator will the flow through an Orifice and the pressure drop. Used for flow measurement and also to discharge water at a known rate.

Frequency and sample rate plot in time

This calculator will provide the resesotr value for resister, from forward voltage and current.

LED resistor calculator