555 Astable Calculator

Use this calculator to find out the time period, capacitor, or resistor values needed to make a 555 astable oscillator. Be careful when calculating for the passives, as some combinations are physically impossible (you will get negative resistances)!

Solve For:	Time Period C R1 R2
Time Period		Hours Minutes Seconds ms µs ns ps
C1		MF KF F mF µF nF pF
R1		MΩ KΩ Ω mΩ µΩ nΩ pΩ
R2		MΩ KΩ Ω mΩ µΩ nΩ pΩ
Result	Ready!
Frequency	N/A
Duty Cycle	N/A
On Time	N/A
Off Time	N/A
	Calculate