# Vitamin A Calculator (IU to mcg RAE)

URL: https://speedycalculator.com/calculators/health/vitamin-a/
Last updated: 2026-10-30

> The vitamin A calculator converts vitamin A amounts between international units (IU) and micrograms of retinol activity equivalents (mcg RAE) for retinol, supplemental beta-carotene and food carotenoids, and compares the result with your RDA and the upper limit.

## Inputs

- Amount (IU)
- Form of vitamin A
- Sex
- Status
- Age (years)

## Results

- Vitamin A
- Your RDA
- Share of your RDA
- Compared with the adult upper limit (3,000 mcg retinol)

## Formula

```
Retinol: 1 IU = 0.3 mcg RAE
Supplemental beta-carotene: 1 IU = 0.15 mcg RAE (2 mcg = 1 mcg RAE)
Dietary beta-carotene: 1 IU = 0.05 mcg RAE (12 mcg = 1 mcg RAE)
Other dietary carotenoids: 1 IU = 0.025 mcg RAE (24 mcg = 1 mcg RAE)
```

## Explanation

Food labels in the US switched from IU to mcg RAE in 2020 because carotenoids from plants are converted to vitamin A much less efficiently than preformed retinol. The upper limit of 3,000 mcg a day applies only to preformed vitamin A (retinol), not to beta-carotene from food.

### How to use the Vitamin A Calculator

- **Amount**
- **Form of vitamin A**
- **Sex**
- **Status**
- **Age**
- Every result field is editable: type into **Vitamin A** and **Amount** plus every other field update to match.

Results update as you type, and every field accepts the units shown in its menu.

### How it works

Enter the amount on the label and choose the form. The calculator converts it to mcg RAE and shows what share of your RDA it provides.

### Inputs explained

FieldWhat to enterAmountIn IUForm of vitamin AChoose one: Retinol / retinyl esters (preformed), Beta-carotene supplement, Beta-carotene from food, Other carotenoids from foodSexChoose one: Male, FemaleStatusChoose one: Not pregnant or breastfeeding, Pregnant, BreastfeedingAgeIn years

### What each result means

- **Vitamin A** = [Amount]×[Form of vitamin A]
- **Share of your RDA** = [Vitamin A]÷[Your RDA]×100

### Example values

How the main result changes when **Amount** changes and everything else stays at the example values above:

Amount (IU)Vitamin A (mcg RAE)2,5007503,7501,1255,0001,5006,2501,8757,5002,25010,0003,000
*Health note: this calculator is for education and screening only and is not a diagnosis or treatment advice. Discuss your results with a qualified clinician.*

## Worked example

Inputs — Amount: 5,000 IU; Form of vitamin A: Retinol / retinyl esters (preformed); Sex: Male; Age: 30 years.

Results — **Vitamin A = 1,500 mcg RAE**; Your RDA = 900 mcg RAE/day; Share of your RDA = 167 %; Compared with the adult upper limit (3,000 mcg retinol) = Well below the limit.

## Key terms

- **RAE**: Retinol activity equivalent.
- **IU**: International unit.

## FAQ

**How many IU of vitamin A do I need?**
900 mcg RAE for men (3,000 IU retinol) and 700 mcg RAE for women (2,333 IU retinol).

**Can you take too much vitamin A?**
Yes – long-term intakes above 3,000 mcg retinol a day can harm the liver, bones and an unborn baby.

**Why do carotenoids count less?**
Only part of beta-carotene from food is absorbed and converted to vitamin A.


## Sources

- [NIH Office of Dietary Supplements – Vitamin A fact sheet for health professionals](https://ods.od.nih.gov/factsheets/VitaminA-HealthProfessional/)