The widespread use of domestic LED lamps raises concerns about harmonic current aggregation when multiple units operate in parallel. This study presents a regression-based method for predicting aggregate current waveforms of identical LED lamps. Measurements conducted in accordance with IEC 61000-4-30:2015 involved 1–24 parallel-connected units of a 12 W lamp under controlled conditions. Individual harmonics through the 40th order were assessed against IEC 61000-3-2 product limits, while components up to the 50th order were retained for PCC-oriented characterization of large-scale aggregation, consistent with IEEE 519-2022. Although the product limits were satisfied, measured THD_I remained at 88.6–92%, dominated by the 3rd, 5th, and 7th harmonics. Within the measured range, per-harmonic regressions were evaluated using R² and RMSE, while reconstructed time-domain waveforms produced NRMSE values of 5–10% relative to measured RMS current. Consistent phase angles indicated predominantly constructive aggregation. The model was then applied to an illustrative scenario of up to 100 identical lamps. Under unchanged lamp and supply conditions, the projection indicated a near-linear increase in RMS current, persistent THD_I of approximately 90%, and continued dominance of low-order odd harmonics. Results beyond 24 lamps represent model-based extrapolation rather than experimental validation. The framework provides a baseline for harmonic current assessment in homogeneous LED installations.