Thermal computing is a promising alternative to electronics, which typically fail in harsh environments such as high temperatures and ionizing radiation. In this work, we built and simulated a thermal calculator based on thermal logic gates that can perform similar operations as their electronic counterparts. We present the design and modeling of thermal AND, OR and NOT logic gates, achieved through the coupling between near-field thermal radiation and MEMS thermal actuation. In the process, we also developed two novel non-linear thermal expansion designs of microstructured chevron beams. These results are significant breakthroughs in the field of thermal computation science and technology as they demonstrate thermal computing at high temperatures based on demonstrated and easy to manufacture Nano Thermo Mechanical diodes and transistors. (C) 2019 Elsevier Ltd. All rights reserved.