Adjust for Inflation - Real Price vs. Nominal Price

For USA (dollar-priced assets):
CPI ticker: FRED:CPIAUCSL

Calculate ratio R:
R = ( y / FRED:CPIAUCSL) where y is the current value

Calculate real price:
Asset symbol * R

Example: calculate real price of Comex gold futures (COMEX:GC1!)

'COMEX:GC1!' * (256.16 / 'FRED:CPIAUCSL')

Note
1) Sometimes it is necessary to put symbol names in 'quotation marks' when performing operations on them.
2) In the examples above, remember to replace the current value in the ratio with the actual current value.