The fundamental problem of economic accounting is to determine a forward‐looking schedule of rentals, user costs or quasi‐rents to provide for the recovery of irreversible investments. The method derived herein relaxes some restrictive assumptions that are common in capital theory. There can be multiple forms of comprehensive capital. Accounting for all forms of capital, including tangible and intangible capital, is symmetrical. The analytical focus becomes one of fixities and frictions and not optimality. Rentals obey inequalities as opposed to marginal conditions. If discounted profit is positive, rentals, depreciation, and capital value are not unique.