This dataset gives the density, thermal expansion coefficient and isothermal compressibility of 7-Methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene (CAS number: 84030-20-6) over a range of temperatures and pressures. The data was measured using an Anton Paar DMA HP density meter. The 7-Methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene (mTBD) had a purity of 100.9 ± 1.4 wt%.