I'd appreciate help with a formula

I need a formula to calculate the following

4.5% of any amount up to and equal to $41,100.00 PLUS 6.00% on any amount above $41,100.

ie $20,000 would be (20,000 x .045) $900.00

ie $50,000 would be [(41,100 x .05) + (8,900 x .060)] $2,383.50

Thanks Peter