Per Diem Budget Calculator
Turn cage counts, per-diem rates, and study duration into a grant-ready animal housing budget in seconds.
Try Moustra freeHow vivarium per diem costs work
Every day an animal is housed in a research vivarium, the institution incurs real costs: labor for husbandry technicians, bedding and feed, facility utilities, cage washing, veterinary oversight, and compliance overhead. To recover these expenses, core vivarium facilities charge a per diem rate — a flat daily fee applied to each occupied cage or each individual animal, depending on the billing model.
Per diem charges can represent the largest single line item in a preclinical study budget, yet they are often underestimated in grant applications because researchers forget to account for acclimation periods, breeding cages that run for most of the year, or cohorts that finish later than planned. A transparent, cohort-by-cohort estimate produced before submission avoids costly budget revisions or no-cost extensions.
Many institutions also apply animal acquisition costs — one-time purchase, shipping, and quarantine fees charged when animals first arrive. This calculator lets you add an acquisition cost per animal so your grand total reflects the true first-year outlay. When you are billing per cage, you can specify how many animals are in each cage to compute acquisition costs accurately.
How to use this budget calculator
- Choose your billing unit — select "Per cage" if your vivarium charges by cage, or "Per animal" if it charges per individual animal. Check your vivarium's rate sheet or business office if you are unsure.
- Add cohorts — click "Add cohort" for each distinct group you plan to house (e.g., breeding colony, experimental group A, control group B). Giving each cohort a clear label makes the exported CSV ready to paste into a budget justification.
- Fill in the numbers — enter the number of cages or animals, the daily rate from your vivarium's schedule, and the total number of days each cohort will be housed. Include acclimation and any post-procedure observation periods.
- Add acquisition costs (optional) — if you are purchasing animals, enter the per-animal acquisition price. For per-cage billing, also enter the number of animals per cage so the calculator can derive the correct acquisition total.
- Export or share — click "Export CSV" to download a table suitable for your grants management system, or copy a shareable link so collaborators can review and adjust the same calculation.
Frequently Asked Questions
What is a per diem rate in animal research?
A per diem rate is the daily fee a vivarium charges to house each cage or animal. Institutions use these daily fees to recover the costs of housing, husbandry, veterinary oversight, and facility overhead. Rates are set by each institution and can vary significantly between facilities and animal species.
How do I budget animal housing costs for a grant?
Start by listing every cohort you plan to house (e.g., breeding cages, study groups, controls). For each cohort, multiply the number of cages or animals by the daily rate and the number of days housed. Add any one-time animal acquisition costs. Sum across cohorts for the grand total. This calculator automates all of those steps so you can paste the output directly into a budget justification.
What is the difference between per-cage and per-animal rates?
Some institutions bill by the cage regardless of how many animals are in it (per-cage rate), while others bill per individual animal (per-animal rate). Using the wrong unit will over- or under-estimate your budget. Check with your vivarium business office to confirm which billing model your facility uses before budgeting.
What does a typical mouse per diem cost?
Per diem rates vary widely by institution, facility, and animal model. As a rough illustration, mouse caging fees at many US academic institutions fall somewhere in the range of $0.50–$2.00 per cage per day, but some facilities are higher or lower. These figures are examples only — always contact your vivarium for the exact rates applicable to your study.
How can I reduce per diem costs in my study?
Common strategies include right-sizing cohorts to the minimum statistically justified number of animals, consolidating animals into fewer cages where welfare rules permit, shortening acclimation periods, timing euthanasia to avoid billing for extra days, and negotiating institutional discounts for large or long-term studies. Moustra's real-time cage tracking helps labs catch idle or over-populated cages before they inflate per diem charges.
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