Slightly stronger than the hot version
The iced Chai Latte, black tea infused with spices over ice with milk, carries 45 mg of caffeine in a Tall, 60 mg in a Grande, and 90 mg in a 24 oz Venti. That runs a little higher than the hot Chai Latte at the same sizes (35 mg Tall, 55 mg Grande, 75 mg Venti), likely down to how the chai concentrate is proportioned over ice.
Either way, chai stays well below coffee: a Grande iced chai’s 60 mg is a fraction of a Grande Caffè Latte (150 mg) or a Grande Pike Place Roast at the top of its range (390 mg).
Against the other iced tea drinks
A Grande iced chai’s 60 mg lands close to a Grande Iced Matcha Latte (65 mg) and above a Grande Iced Black Tea (25 to 30 mg), since chai is built from a more concentrated tea base than a plain brewed iced tea.
Because the difference between hot and iced chai is small in absolute terms, choosing between them is really a question of temperature preference rather than caffeine management.
Where it fits in a day
At 60 mg, a Grande is far under the 200 mg single dose EFSA assessed as safe for healthy adults. Six Grandes, 360 mg, would be needed to approach the 400 mg daily figure the FDA cites. In pregnancy, where ACOG uses a 200 mg daily ceiling, three Grandes, 180 mg, still fit under the daily allowance.