The sponsor is requiring that the proposed personnel effort be shown in man-hours. How do I do this?

If MIT is responding to a competitive solicitation requiring man-hours, proposals sometimes include estimated man-hours conversion rates, with the following statement: MIT’s accounting system does not support estimating, accumulating and reporting personnel costs on a man-hour basis. Estimated man-hour conversion information is provided for sponsor proposal evaluation purposes only.  If an award is made, costs will be accumulated and reported on a man-month basis.