<p>The ability of bamboo to store carbon in its biomass varies depending on species, site conditions, and management practices. In Nepal, bamboo is widely distributed outside forest areas, often with little or no management, making it essential to develop biomass models to quantify its carbon stock potential in such settings. Therefore, this study aims to develop species-specific aboveground biomass models for <i>Bambusa teres</i> Buch.-Ham. ex Munro and <i>Bambusa tulda</i> Roxb. in non-forest areas of Nepal. A total of 104 culms (54 <i>B. teres</i>, 50 <i>B. tulda</i>) were sampled; diameter at breast height (DBH) and height ranged 4.0–9.4&#xa0;cm and 8.3–22.4&#xa0;cm in <i>B. teres</i>, 4.3–10.5&#xa0;cm and 7.0–20.7&#xa0;cm in <i>B. tulda</i>. Various regression models (linear, power, and exponential) were tested using DBH and height as independent variables and biomass components (foliage, branch, culm, and total aboveground biomass) as dependent variables. Due to the small sample size, the leave-one-out cross-validation method was used for model validation. Our findings indicate that <i>B. tulda</i> had significantly higher mean DBH, foliage, and branch biomass than <i>B. teres</i>. The power model incorporating both DBH and height (M9) performed best (adj. R² &gt; 0.80) for predicting culm biomass and total aboveground biomass in both species. However, none of the models accurately predicted foliage biomass and branch biomass (adj. R² &lt; 0.55), suggesting that allometric models may not be suitable for these components. This study aids in quantifying bamboo carbon and establishing a database for studied species, facilitating Nepal’s entry into the carbon credit market. We recommend development of species- and age-specific allometric models for other bamboo species along with belowground biomass models to enhance bamboo carbon quantification in non-forest settings in Nepal.</p>