This paper investigates contractual definitions of net income and net worth and the cross-sectional variation in definitions of net income in a large sample of private debt contracts to shed light on the debt contracting demand for accounting numbers. The descriptive evidence indicates that removing transitory earnings is one principal concern in the measurement of earnings but not in the measurement of net worth. In the extreme, contracts are never written on comprehensive income as an earnings concept, whereas accumulated other comprehensive income is included in net worth in most contracts. In contrast, conservative adjustment, in the sense of including certain types of negative earnings but not the corresponding positive earnings, does not seem to be a primary consideration in measuring net income and net worth. Cross-sectionally, I find that net income is more likely to be defined differently from the GAAP when net income plays a more important role in a contract, when the loan maturity is longer, and when transitory earnings are less useful for debt contracting. Collectively, the evidence shows that debt contracting parties choose contracting variables in a manner consistent with efficient contracting, and that transitory earnings are relatively less useful in measuring firm performance for debt contracting.