How long and how heavy the baby is from week 4 to week 42, and what they're about the size of, in one chart.
These are typical figures. Every baby grows to their own pattern, and a scan measures your own baby.
Until week 20 a baby is measured crown to rump, curled up with the legs not counted. From week 20 it's head to heel, which is why the length jumps at week 20 rather than climbs.
Week 4: a poppy seed, 0.2 cm (0.1 in), under 1 g (under 0.1 oz) Week 5: an apple seed, 0.3 cm (0.1 in), under 1 g (under 0.1 oz) Week 6: a sweet pea, 0.6 cm (0.2 in), 1 g (under 0.1 oz) Week 7: a blueberry, 1 cm (0.4 in), 1.5 g (under 0.1 oz) Week 8: a raspberry, 1.6 cm (0.6 in), 2 g (under 0.1 oz) Week 9: a green olive, 2.3 cm (0.9 in), 3 g (0.1 oz) Week 10: a strawberry, 3.1 cm (1.2 in), 4 g (0.1 oz) Week 11: a fig, 4.1 cm (1.6 in), 7 g (0.2 oz) Week 12: a lime, 5.4 cm (2.1 in), 14 g (0.5 oz) Week 13: a pea pod, 7.4 cm (2.9 in), 23 g (0.8 oz) Week 14: a lemon, 8.7 cm (3.4 in), 43 g (2 oz) Week 15: an apple, 10.1 cm (4 in), 70 g (2 oz) Week 16: an avocado, 11.6 cm (4.6 in), 100 g (4 oz) Week 17: a pomegranate, 13 cm (5.1 in), 140 g (5 oz) Week 18: a bell pepper, 14.2 cm (5.6 in), 190 g (7 oz) Week 19: a mango, 15.3 cm (6 in), 240 g (8 oz) Week 20: a banana, 25 cm (9.8 in), 300 g (11 oz) Week 21: a carrot, 26.5 cm (10.4 in), 360 g (13 oz) Week 22: a papaya, 28 cm (11 in), 430 g (15 oz) Week 23: a grapefruit, 29 cm (11.4 in), 500 g (1 lb 2 oz) Week 24: an ear of corn, 30 cm (11.8 in), 600 g (1 lb 5 oz) Week 25: a cauliflower, 32.5 cm (12.8 in), 680 g (1 lb 8 oz) Week 26: a lettuce, 35 cm (13.8 in), 760 g (1 lb 11 oz) Week 27: a swede, 36 cm (14.2 in), 875 g (1 lb 15 oz) Week 28: a coconut, 37 cm (14.6 in), 1 kg (2 lb 3 oz) Week 29: a butternut squash, 38.5 cm (15.2 in), 1.15 kg (2 lb 9 oz) Week 30: a cabbage, 40 cm (15.7 in), 1.3 kg (2 lb 14 oz) Week 31: a Chinese cabbage, 41 cm (16.1 in), 1.5 kg (3 lb 5 oz) Week 32: a courgette, 42 cm (16.5 in), 1.7 kg (3 lb 12 oz) Week 33: a celery head, 43.5 cm (17.1 in), 1.9 kg (4 lb 3 oz) Week 34: a pineapple, 45 cm (17.7 in), 2.1 kg (4 lb 10 oz) Week 35: a honeydew melon, 46 cm (18.1 in), 2.35 kg (5 lb 3 oz) Week 36: a romaine lettuce, 47 cm (18.5 in), 2.6 kg (5 lb 12 oz) Week 37: a cantaloupe, 48 cm (18.9 in), 2.8 kg (6 lb 3 oz) Week 38: a leek, 49 cm (19.3 in), 3 kg (6 lb 10 oz) Week 39: a mini watermelon, 50 cm (19.7 in), 3.2 kg (7 lb 1 oz) Week 40: a small pumpkin, 51 cm (20.1 in), 3.4 kg (7 lb 8 oz) Week 41: a jackfruit, 51.5 cm (20.3 in), 3.55 kg (7 lb 13 oz) Week 42: a watermelon, 52 cm (20.5 in), 3.7 kg (8 lb 3 oz)