Uncertainties in the measurements necessary for the calculation of amino acid age estimates and paleotemperatures can be propagated through age and temperature equations to yield estimates of precision. It is found that aIle/Ile ratios can be used to calculate numerical ages with a precision generally no better than ±40-50% if the age equation is not calibrated locally and with a precision approaching 15% if appropriate calibration samples are available locally. The effective diagenetic temperature of a sample of known age can be calculated to within about 2°C, although the local relationship between ground and air temperatures may add additional uncertainty when interpreting the effective temperature in terms of climate. The effective temperature for an interval of time bracketed by samples of known age can be known to within about 2-4°C under favorable circumstances. The change in effective temperature between an interval of time bracketed by two samples of known age and the period of time following that interval can be calculated to within 1-2°C in may instances.