See the healthy weight-gain range for a twin pregnancy by pre-pregnancy BMI, based on IOM/CDC twin guidelines. A supportive general guide — not a target — to discuss with your maternity team.
This shows the general healthy weight-gain range for a twin pregnancy recommended in guidelines (IOM/CDC), based on pre-pregnancy BMI. Twins need more gain than a single baby. It’s a guide, not a target to police — and pregnancy is never a time for dieting. Your maternity team will advise what’s right for you.
About you
kg
cm
of ~37
Pre-pregnancy weight and height set your BMI category, which guidelines use to suggest a healthy total gain for twins. Twin pregnancies are often considered full term earlier (around 37 weeks).
Recommended total gain (twins)
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Enter your details
Pre-pregnancy BMI
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BMI category
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Typical gain by this week
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General guidance from IOM/CDC twin ranges, not medical advice and not a personal target. Multiple pregnancies are higher-risk and closely monitored — your maternity team gives the guidance that’s right for you. If weight or eating feels stressful, the National Alliance for Eating Disorders helpline can also help.
Use this free twin pregnancy weight gain calculator to see the healthy weight-gain range recommended when expecting twins, based on your pre-pregnancy BMI. It’s a supportive guide, not a target to police.
What this twin weight gain calculator does
This twin pregnancy weight gain calculator uses the IOM/CDC twin guidelines to show a healthy total gain range for your pre-pregnancy BMI. Twins call for more gain than a single baby, and these ranges reflect that.
Recommended twin weight gain by BMI
Pre-pregnancy BMI
Recommended gain (twins)
Healthy weight (18.5–24.9)
16.8–24.5 kg (37–54 lb)
Overweight (25–29.9)
14.1–22.7 kg (31–50 lb)
Obese (30+)
11.3–19.1 kg (25–42 lb)
Underweight (under 18.5)
No formal range — your team will advise
How twin weight gain differs from a single pregnancy
Twins need more total gain — often around 16–24 kg for a healthy starting weight versus 11–16 kg for one baby — and gaining steadily in early and mid pregnancy is especially valued, because twins often arrive earlier. Twin pregnancies are also monitored more closely overall.
A gentle note on weight with twins
Carrying twins is demanding, and your body needs steady nourishment — this is not a time for dieting or weight loss. Ranges are a general guide and individual needs vary. If weight or eating feels stressful, please talk to your maternity team, who can offer kind, personal support.
How to use the twin weight gain calculator
Enter your pre-pregnancy weight and height.
Add your current week if you’d like a by-now estimate.
See the recommended total range for twins.
Twin Pregnancy Weight Gain FAQ
How much weight should I gain with twins?
It depends on your pre-pregnancy BMI: roughly 16.8–24.5 kg (37–54 lb) for a healthy starting weight, with somewhat lower ranges if you began overweight or obese. The calculator shows yours.
Why is twin weight gain higher than for one baby?
Because you're nourishing two babies plus extra placental and fluid weight, twin guidelines recommend more total gain than a singleton pregnancy.
What if I started underweight?
There isn't a formal IOM twin range for underweight, so the calculator suggests asking your maternity team, who will set an individual goal for you.
Should I diet during a twin pregnancy?
No — pregnancy isn't a time for dieting or weight loss, and twins are especially demanding. Steady nourishment matters; raise any concerns with your maternity team.
When do twins usually arrive?
Twin pregnancies are often considered full term around 37 weeks and frequently arrive earlier, which is why steady early and mid-pregnancy gain is valued.
Is the twin weight gain calculator free?
Yes, this twin pregnancy weight gain calculator is completely free, needs no sign-up, and gives instant results in your browser.
