San Marino is about 2,825 times smaller than Washington.

Washington is approximately 172,348 sq km, while San Marino is approximately 61 sq km, making San Marino 0.04% the size of Washington. Meanwhile, the population of Washington is ~6.7 million people (6.7 million fewer people live in San Marino).
Tip: This to-scale comparison of Washington vs. San Marino uses the Mercator projection, which distorts the size of regions near the poles.