Human Dose Calculator — Nonclinical Academy

Calculation Mode

What do you want to calculate?

Human reference weight

Enter the NOAEL from each species tested below. The tool scales each to an HED using BSA conversion, identifies the most sensitive species, and applies the safety factor (10×) to calculate the MRSD for first-in-human (non-oncology).

Animal Study Data

Check the species you have data for, then enter the dose (NOAEL) and body weight. Km factors are from FDA 2005 Table 1.

Result

Maximum Recommended Starting Dose

FDA 2005 · Based on most sensitive species

Awaiting Data

Enter at least one species

Reference: K_m factors & quick conversions (FDA 2005 Table 1)

Note: "K_m" here is the body-weight-to-body-surface-area conversion factor (units: kg/m²), defined as body weight ÷ body surface area. It is NOT the Michaelis constant from enzyme kinetics. HED (mg/kg) = animal dose (mg/kg) × (K_m,animal / K_m,human).

Species	Ref Wt (kg)	K_m (kg/m²)	Convert animal mg/kg dose to →
Species	Ref Wt (kg)	K_m (kg/m²)	HED mg/kg divide by	mg/m² multiply by
Mouse	0.020	3	12.3	3
Hamster	0.080	5	7.4	5
Rat	0.150	6	6.2	6
Guinea pig	0.400	8	4.6	8
Rabbit	1.800	12	3.1	12
Dog	10	20	1.8	20
Monkey (cyno/rhesus)	3	12	3.1	12
Human	60	37	—	37

Quick examples:

Rat dose of 60 mg/kg → HED = 60 ÷ 6.2 = 9.7 mg/kg
Dog dose of 30 mg/kg → HED = 30 ÷ 1.8 = 16.7 mg/kg
Monkey dose of 20 mg/kg → mg/m² = 20 × 12 = 240 mg/m²