Right ventricular (RV) maximal power (PWR_mx) is dependent on preload. The objective of this study was to test our hypothesis that the PWR_mx vs end-diastolic volume (EDV) relationship, analogous to the load-independent stroke work vs EDV relationship (PRSW), is linear, with x-axis intercept (V0_PWR) corresponding to PRSW intercept (V0_SW). If our hypothesis is correct, the preload sensitivity of PWR_mx could be eliminated by adjusting for EDV and V0_PWR. Ten dogs were instrumented with pulmonary flow probe, micromanometers, and RV conductance catheter. Data were obtained during bicaval occlusions under various conditions and fitted to PWR_mx = a^.(EDV- V0_PWR). The PWR_mx vs EDV relationship did not deviate from linearity ( = 1.09, P NS vs 1), and V0_PWR correlated with V0_SW (r = 0.93, P <0.0001). V0_PRW was related to steady-state EDV and left ventricular end-diastolic pressure, allowing for estimation of V0_PWR (V0_Est) and single beat PWR_mx preload adjustment. Dividing PWR_mx by the difference of EDV and V0_PWR (PAMP_V0pwr) eliminated preload dependency down to 50% of baseline EDV. PWR_mx adjustment using V0_Est (PAMP_V0est) showed similar preload independency. Enhancing contractility increased PAMP_V0pwr and PAMP_V0est from 176 ± 52 to 394 ± 205 W/ml^.10⁴ and 145 ± 51 to 404 ± 261 W/ml^.10⁴, respectively, accompanied by an increase of PRSW from 13.0 ± 4.5 to 29.7 ± 16.4 mm Hg (all P <0.01). PAMP_V0pwr and PAMP_V0est correlated with PRSW (r = 0.85; r = 0.77; both P <0.001). Numerical modeling confirmed experimental data. Thus, preload adjustment of PWR_mx should consider a linear PWR_mx vs EDV relationship with distinct V0_PWR. PAMP_V0pwr is a preload-independent estimate of RV contractility that may eventually be determined non-invasively.