Top: comparison of LoTSS-DR1 differential source counts using “mask d” and SKADS 151 MHz and T-RECS “wide” 150 MHz simulations. The grey band corresponds to a ±20% variation of the LoTSS flux density scale due to uncertainties in the flux density calibration. Bottom: contributions from AGNs and SFGs in the T-RECS “wide” differential source counts as compared to the total LoTSS-DR1 differential source counts. All: error bars are due to Poisson noise in each flux density bin, which have equal bin width in log₁₀(S).