An extensive feasibility study on magnetic heat pumps, based on simple engineering calculus, reveals a good potential to build energy-efficient and cost-effective devices. The energy efficiency of a magnetic heat pump is better and the costs are slightly higher than for a conventional gas compression/expansion heat pump. This cost evaluation is based on a magneto caloric material prize, which probably will not be the minimal one being achieved in the near future. This example of a feasibility study may be applied exactly in the same manner to evaluate the potential (energy efficiency and costs) of similar applications; which are e.g. magnetic refrigerators or magnetic power conversion devices designed to operate in other market areas. An extensive feasibility study on magnetic heat pumps, based on simple engineering calculus, reveals a good potential to build energy-efficient and cost-effective devices. The energy efficiency of a magnetic heat pump is better and the costs are slightly higher than for a conventional gas compression/expansion heat pump. This cost evaluation is based on a magneto caloric material prize, which probably will not be the minimal one being achieved in the near future. This example of a feasibility study may be applied exactly in the same manner to evaluate the potential (energy efficiency and costs) of similar applications; which are e.g. magnetic refrigerators or magnetic power conversion devices designed to operate in other market areas.