Folic acid Pediatric Dose Calculator
Age-based folic acid dosing for children — <1 year: 0.5 mg per dose · once daily; ≥1 year: 5 mg per dose · once daily. Enter age and weight for the dose in mg and syrup mL or tablets.
Pediatric dosing
Folate deficiency / megaloblastic anaemia
Folic acid dose chart by age and weight
Folate deficiency / megaloblastic anaemia. Weights are WHO/IAP reference medians for age — always dose on the measured weight.
| Age | Weight | Dose (mg) | Syrup 5 mg/5 mL (where available) | Frequency |
|---|---|---|---|---|
| 15 days | 3.8 kg | 0.5 mg | 0.5 mL | Once daily |
| 1 month | 4.3 kg | 0.5 mg | 0.5 mL | Once daily |
| 3 months | 6.1 kg | 0.5 mg | 0.5 mL | Once daily |
| 6 months | 7.6 kg | 0.5 mg | 0.5 mL | Once daily |
| 9 months | 8.6 kg | 0.5 mg | 0.5 mL | Once daily |
| 1 year | 9.3 kg | 5 mg | 5 mL | Once daily |
| 18 months | 10.6 kg | 5 mg | 5 mL | Once daily |
| 2 years | 11.8 kg | 5 mg | 5 mL | Once daily |
| 3 years | 14.1 kg | 5 mg | 5 mL | Once daily |
| 4 years | 16.2 kg | 5 mg | 5 mL | Once daily |
| 5 years | 17.5 kg | 5 mg | 5 mL | Once daily |
| 6 years | 19 kg | 5 mg | 5 mL | Once daily |
| 8 years | 24.4 kg | 5 mg | 5 mL | Once daily |
| 10 years | 31.1 kg | 5 mg | 5 mL | Once daily |
| 12 years | 39.4 kg | 5 mg | 5 mL | Once daily |
Strengths in the calculator
- Syrup 5 mg/5 mL (where available) (Oral)
- Tablet 0.5 mg (Oral)
- Tablet 5 mg (Oral)
Different strength on your bottle? Use “Different strength on the bottle?” under the result.
Safety
Pregnancy and breastfeeding
Legacy FDA category A. Recommended before conception and in early pregnancy (neural-tube defect prevention).
Compatible with breastfeeding.
Clinical notes
Never treat megaloblastic anaemia with folic acid alone until vitamin B12 deficiency is excluded (risk of subacute combined degeneration).
Adult and adolescent (≥40 kg) dose
5 mg — Once daily (max 5 mg per dose).
Periconceptional prevention: 0.4 mg daily (5 mg if high risk).
Other names and brands
Also known as Folate, Vitamin B9.
- India: Folvite
Brand examples only — products and strengths vary by country. Always check the label.
Frequently asked questions
What is the folic acid dose for children?
Folate deficiency / megaloblastic anaemia: <1 year: 0.5 mg per dose · once daily; ≥1 year: 5 mg per dose · once daily. Usual duration: Up to 4 months. Always use the child's measured weight and check the strength on the bottle.
How many mL of syrup 5 mg/5 mL (where available) for an 11.8 kg child?
For folate deficiency / megaloblastic anaemia, an 11.8 kg child (about 2 years) needs 5 mg per dose — 5 mL of Syrup 5 mg/5 mL (where available), once daily. Recalculate with the child's actual weight.
From what age can folic acid be given?
Age range in PediaRx: Birth – adult. Each indication can have its own age and weight limits, shown with its regimen.
Is folic acid safe in pregnancy?
Legacy FDA category A. Recommended before conception and in early pregnancy (neural-tube defect prevention).
Sources and editorial process
- BNF for Children — Folic acid — NICE / BMJ Group / Royal Pharmaceutical Society
Dosing data last updated 2026-09-27. PediaRx is built and maintained by Dr. Shounak Pal, MBBS (Medical Officer, Government of West Bengal, India — founder and developer of PediaRx). Every regimen is encoded with explicit units, maximum doses and age/weight limits and is checked by automated tests before publication. Report an error: hello@pediarx.com.
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Clinical disclaimer: reference tool for qualified health professionals. Verify every dose against current guidance and the product label before prescribing.
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