Resistor calculator (series and parallel)

If you need a non-standard resistor value you could probably realize a close match using two resistor. If you use two resistor in series it is quite easy to figure out which values give the best match; on the other hand, using a parallel connection it is not so easy (at least for me) to find a good combination.
This resistor calculation tool shows which combinations of two resistors (series or parallel) gives a match better than the closest standard value, for the E12 (10%), E24 (5%) and E96 (1%) series.

Resistor series to use for the calculations: 
E12 (10 %) series
E24 (5 %) series
E96 (1 %) series


Desided Resistance, R :  ohm