CaloBox - Indirect Calorimetry

A novel system for the indirect calorimetry of mice, rats, birds, and other small animals. Simply connect the CaloBox with an animal cuvette, turn on air flow, and press “Start” for a measurement.
Common applications are: Animal metabolism, nutrition, heat regulation, thermoregulation, bioenergetics, activity, animal behavior, energy balance, resting metabolic rate, energetics of locomotion, and many more.
The Calobox automatically measures and calculates typical indirect calorimetry parameters such as metabolic rate, energy expenditure (EE), and respiratory exchange ratio (RER). Video introduction.

The CaloBox was developed by Prof. Dr. Gerhard Heldmaier (Philipps-Universität Marburg, Germany). Read what Prof. Heldmaier says about the CaloBox here.

The PhenoSys CaloBox is a PhenoSys Collaboration product. These products are brought to market together with the scientists who developed them. The CaloBox is a joint product of Prof. Dr. Gerhard Heldmaier and PhenoSys.


  • Internal pumps for air flow through animal cuvette 30..150 L/h
  • Down to 4 sec reliable measurement interval
  • No drying of sample or reference air required
  • Measurement of O2 , CO2, and water vapor content in sample air; Comparison to reference air
  • Automatic adjustment of gas sensors with reference air in preset intervals (zero adjustment)


Calculation of metabolic rates:

  • O2 consumption per unit time (V′O2 )
  • Carbon dioxide production (V′CO2 )
  • Water vapor evaporation (V′H2O)
  • Respiratory exchange ratio (RER, RQ)


Calculates energy expenditure (EE) based on V′O2 and RER

Check out the Wikipedia page for a basic introduction into the topic.


Dimensions35 x 30 x 15.8 cm
Weight3.5 kg
Mass flowmeter for sample air / Response time / Repeatability 0...5 sLpm (0….300 L/h) / 60 msec / +- 0.5%
Electrochemical O2-cell. Range / response time / accuracy0….25 Vol% / 12 sec / <1% @ 21 Vol%
CO2 measurement, NDIR-cell (non dispersive infrared): range / response time / accuracy0...0.5 Vol% / 20sec / +-30 ppm
HT-Sensor, relative humidity resolution / temperature sensor resolution0.025% / 0.04°C
Thermocouple Type T, Cu-Const, resolution+/- 0.1 °C
Membrane pumpslonglife with brushless dc motor

The CaloBox – Push-button calorimetry

CaloBox Set-up with small animal cuvette and Laptop

Reliable and user-friendly technology

Reliable and user-friendly technology

Heldmaier, G., Braulke, L., Flick, J. et al. Silencing of ultradian rhythms and metabolic depression during spontaneous daily torpor in Djungarian hamsters. J Comp Physiol B (2024).

Harding, C.D., Walker, K.M.M., Hackett, T.D. et al. Ultrasonic vocalisation rate tracks the diurnal pattern of activity in winter phenotype Djungarian hamsters (Phodopus sungorus). J Comp Physiol B (2024).

van der Vinne, V., McKillop, L.E., Wilcox, S.L. et al. Methods to estimate body temperature and energy expenditure dynamics in fed and fasted laboratory mice: effects of sleep deprivation and light exposure. J Comp Physiol B (2024).

Elfers, K., Armbrecht, Y., Brede, M., Mazzuoli-Weber, G., Heldmaier, G., Breves, G. (2022). How much does it cost? Teaching physiology of energy metabolism in mice using an indirect calorimetry system in a practical course for veterinary students. Adv Physiol Educ, 46: 145-157

Wellbrock, A. H. J., Eckhardt, L. R. H., Kelsey, N. A., Heldmaier, G., Rozman, J., Witte, K. (2022). Cool birds: first evidence of energy-saving nocturnal torpor in free-living commonswifts Apus apus resting in their nests. Biol Lett, 18: 20210675

Yamagata, T., Kahn, M. C., Prius-Mengual, J., Meijer, E., … & Vyazovskiy, V. V. (2021). The hypothalamic link between arousal and sleep homeostasis in mice. PNAS, 118(51), e2101580118.

Oelkrug, R., Krause, C., Herrmann, B., Resch, J., Gachkar, S., El Gammal, A. T., … & Mittag, J. (2020). Maternal Brown Fat Thermogenesis Programs Glucose Tolerance in the Male Offspring. Cell Reports, 33(5), 108351.

Martire, V. L., Berteotti, C., Bastianini, S., Alvente, S., Valli, A., Cerri, M., … & Zoccoli, G. (2020). The physiological signature of daily torpor is not orexin dependent. J Comp Physiol B.; 190(4):493-507.

Johann, K., Cremer, A. L., Fischer, A. W., Heine, M., Pensado, E. R., Resch, J., … & Astiz, M. (2019). Thyroid-hormone-induced browning of white adipose tissue does not contribute to thermogenesis and glucose consumption. Cell reports, 27(11), 3385-3400.