Tipping customs can vary widely depending on the country and culture you are in. In some places, tipping may not be expected or customary for small bills or low-cost meals. However, in other regions, tipping is considered standard regardless of the bill amount.
If you are in a country where tipping is customary, a general guideline is to tip around 15% to 20% of the total bill before taxes. However, tipping a percentage for very low bills may not be practical, and you might consider leaving a flat amount.
For a $5 dine-in bill, you could consider leaving a tip of $1 to $2, or even rounding up the total bill to a more convenient amount (e.g., paying $7 in total).
Ultimately, tipping is a personal choice, and you can consider factors like the quality of service, your budget, and local customs when deciding on the tip amount. If you are unsure about tipping norms in a specific country or region, you can ask locals or look up tipping customs for that area.