1. **State the problem:** Find the percent equivalent of the fraction $\frac{1}{400}$.\n\n2. **Formula:** To convert a fraction to a percent, multiply the fraction by 100:\n$$\text{Percent} = \frac{\text{Numerator}}{\text{Denominator}} \times 100$$\n\n3. **Apply the formula:**\n$$\frac{1}{400} \times 100$$\n\n4. **Calculate:**\n$$\frac{1 \times 100}{400} = \frac{100}{400}$$\n\n5. **Simplify the fraction:**\n$$\frac{\cancel{100}}{\cancel{400}} = \frac{1}{4}$$\n\n6. **Convert to decimal:**\n$$\frac{1}{4} = 0.25$$\n\n7. **Final answer:**\n$$0.25\%$$\n\nSo, $\frac{1}{400}$ is equal to 0.25 percent.