For those running video websites, have you ever encountered this situation: your traffic seems normal this month, but the bill at the end of the month is shockingly high? Or conversely, you feel you've controlled costs well, but the final tally shows you're still losing money? The problem likely lies in the billing model—you haven't understood the 95% billing system and have already paid for it.

　　Let's first discuss why 95% billing exists. Many people think bandwidth billing is "pay as you go," like utility bills. But that's not the case.

　　Traditional bandwidth billing methods are twofold: peak bandwidth billing and traffic-based billing.

　　Peak bandwidth billing is particularly harsh. For example, if your video website experiences a traffic peak between 8 PM and 10 PM, with bandwidth surging to 100Mbps, then even if only those 5 minutes of that day are at 100Mbps, and no one watches for the other 23 hours, you'll still be billed based on the 100Mbps peak usage for that entire day. This is like eating a 200 yuan buffet during the lunch rush, but skipping breakfast and dinner. The restaurant owner tells you, "Today's bill is based on lunch, 200 yuan." You'd definitely feel uncomfortable.

　　What about billing by usage? It seems fair—you pay for what you use. But the problem is, video site traffic fluctuates wildly. Normally there might only be a few dozen users online, but suddenly, a promotion or a video goes viral, and traffic skyrockets. Billing by usage means that the cost during peak days can wipe out your entire monthly savings.

　　So, clever cloud providers came up with a compromise—95% billing. Its core logic is: I acknowledge there will be sudden peaks, but those extreme peaks don't represent your normal usage. We cut off the highest 5% and charge based on the highest remaining value.

　　This is like a teacher grading students: removing the highest and lowest scores, what's left is the true level.

　　How exactly is the 95% billing calculated? Let's walk through it step by step.

　　I know seeing formulas can be daunting, but this isn't difficult at all. I guarantee you'll be able to explain it clearly to others after listening.

　　Step 1: Sampling

　　The cloud provider continuously records your server's bandwidth usage in 5-minute intervals. Once every 5 minutes, 12 times per hour, 24 hours a day, that's 288 sampling points per day, and 8640 points per month. These sampling points record your "outbound" and "inbound" bandwidth values, and the larger of the two is taken as the bandwidth at that point in time.

　　Step 2: Sorting

　　After obtaining the 8640 bandwidth values ​​for the month, they are sorted in descending order of size. The largest value is at the beginning, and the smallest at the end.

　　Step 3: Cutting the Top 5%

　　This step is the essence of the 95% billing system. 8640 points multiplied by 5% equals 432 points. In other words, the 432 highest bandwidth sampling points from your current month are simply discarded and won't be charged. What do these 432 points represent? With 30 days in a month, 432 points equate to 21.6 hours of peak time. This means you have approximately 21 hours of "no-penalty" time each month—during which, even if your bandwidth spikes significantly, it won't be included in your bill.

　　Step Four: Calculate the Remaining Highest Value

　　After removing the top 5%, the highest bandwidth value among the remaining points is your billed bandwidth for this month.

　　In short: Your broadband fee for this month is calculated based on the "highest peak value remaining after removing the highest 21 hours."

　　For example: Suppose you have 8640 sampling points this month, and the top few dozen points are concentrated on two days when a certain video goes viral, causing bandwidth spikes to 200Mbps. But after removing those 432 highest points, the remaining highest value might only be 80Mbps. In that case, you will only be charged for 80Mbps, not 200Mbps.

　　Two possible variations of 95% billing: Daily 95% and Monthly 95%

　　In actual business, 95% billing has two different implementations, which you need to understand to avoid pitfalls.

　　Monthly 95% billing, as mentioned above, uses the entire calendar month as a unit, grouping all sampling points together and sorting them to remove peaks. This model is suitable for scenarios with relatively regular traffic fluctuations and occasional sudden peaks.

　　Daily 95% billing, on the other hand, calculates billing separately for each day. 288 sampling points are taken each day, the highest 5% are removed, and the 95% peak value for that day is obtained. Then, at the end of the month, this daily value is summarized.

　　These two models place completely different demands on suppliers. Monthly 95% allows you to "hide your weaknesses"—poor quality on a few days is acceptable as long as the overall monthly performance is decent, the bill won't look too bad. However, daily 95% is subject to daily scrutiny; if something goes wrong on a particular day, the 95% peak value for that day will be explicitly included in the monthly settlement.

　　For video websites, if your daily traffic curve is relatively stable, there is little difference between daily and monthly 95% billing. However, if you're the type of user who gets little attention during the week but suddenly becomes popular on weekends, the 95% monthly plan is more favorable—because it can use a large number of off-peak sampling points to lower your ranking.

　　Another unavoidable concept: Guaranteed Bandwidth

　　An important concept in the 95% billing system is "guaranteed bandwidth" or "guaranteed percentage."

　　What is a guaranteed percentage? It means that even if you barely use bandwidth for a month, the provider will still charge a minimum fee. This guaranteed percentage is usually a percentage of the 95% billing result, such as 30% or 50%.

　　Why is a guaranteed percentage necessary? Because cloud providers reserve bandwidth resources for you, and even if you don't use them, you can't sell these resources to others. Guaranteed bandwidth is used to cover this cost.

　　In actual billing, the final paid bandwidth is the greater of the "guaranteed bandwidth" and the "bandwidth calculated by 95%." In other words, if your actual usage doesn't even reach the guaranteed minimum, you'll still have to pay the guaranteed minimum.

　　For example: Your contract with the provider guarantees a minimum of 100Mbps. This month, the 95% billing only yields 50Mbps, so unfortunately, you'll still be charged at 100Mbps. But if the 95% billing yields 200Mbps, then you'll be charged at 200Mbps.

　　This mechanism is fair to both parties: the provider guarantees a basic revenue, and you can enjoy the benefits of flexible scaling—no extra charge for short-term spikes.

　　Why should video websites pay special attention to this?

　　Those who run video websites should understand this well; the traffic characteristics of video services are very suitable for 95% billing.

　　First, video traffic naturally has peaks and troughs. Fewer people watch during the daytime, peak hours are after get off work and on weekends, and almost no one watches in the early morning. If you charge based on peak hours, your costs are essentially tied to those two or three hours at night. 95% billing cuts off the highest 5%, effectively exempting you from the daily peak periods.

　　Second, video websites often have "viral content." A video suddenly goes viral, instantly attracting a large influx of users, causing bandwidth to spike significantly in a short period. This situation won't cause a sudden surge in billing under 95% billing because those extreme sampling points will be treated as "outliers" and excluded.

　　Third, many cloud providers offer additional flexible scaling capabilities for 95% billing users. For example, if you purchase a guaranteed bandwidth of 100Mbps, it can automatically scale to 300Mbps or even higher during peak periods. The excess bandwidth is not included in the guaranteed minimum but is billed through 95% billing. This is practically tailor-made for video websites.

　　However, 95% billing isn't a panacea; there are a few pitfalls you should be aware of.

　　The threshold is not low. 95% billing is usually not the default option; you need to actively apply for it, and there are thresholds. Most providers require a certain monthly spending amount or a minimum bandwidth of 300Mbps. Small-scale individual website owners may not meet these thresholds.

　　Billing has a lag. 95% billing is billed on a calendar month basis, so you can only see the previous month's charges the following month. This means you can't monitor costs in real time, and by the end of the month, it's too late to adjust if you discover you've exceeded your budget.

　　It's not suitable for low-traffic businesses. If your bandwidth consistently falls below 100Mbps, the 95% billing model might not be cost-effective. Because of the guaranteed minimum bandwidth, you might actually pay more than you would for data usage alone.

　　Different vendors have different calculation details. Some vendors have specific rules for calculating valid days—if the bandwidth on a given day is below a certain threshold (e.g., 10Kbps), that day is not counted as a valid day and is not included in the billing. This detail will affect the final bill, so be sure to clarify this before signing the contract.

　　The 95% billing model is essentially a "risk-sharing, flexibility-sharing" billing model. It acknowledges the inherent volatility of internet services and, by removing the highest 5% peak usage, makes the bill more closely reflect your "normal usage." For video websites, this might be the most cost-effective billing model—because you enjoy the flexibility of peak-hour scaling without paying for those extreme peaks. However, this is contingent on understanding its calculation rules, knowing your own traffic characteristics, and choosing the right provider and billing model. Otherwise, this "for your own good" mechanism might leave you bewildered by your bill at the end of the month.