You can get an idea of the relationship between C14 and age at the Carbon Dating calculator page. Modern standard The principal modern radiocarbon standard is N.I.S.T (National Institute of Standards and Technology; Gaithersburg, Maryland, USA) Oxalic Acid I (C2H2O4). Oxalic acid I is N.I.S.T designation SRM 4990 B and is termed HOx1. Use the properties of exponentials and logarithms to learn how carbon dating works. This lesson covers properties of a natural log and rules of... Carbon 14 Dating Calculator To find the percent of Carbon 14 remaining after a given number of years, type in the number of years and click on Calculate.