Saint Pierre and Miquelon is about 4 times bigger than British Indian Ocean Territory.

British Indian Ocean Territory is approximately 60 sq km, while Saint Pierre and Miquelon is approximately 242 sq km, making Saint Pierre and Miquelon 303% larger than British Indian Ocean Territory.
Tip: This to-scale comparison of British Indian Ocean Territory vs. Saint Pierre and Miquelon uses the Mercator projection, which distorts the size of regions near the poles.
Compare further: Saint Pierre and Miquelon vs. British Indian Ocean Territory