🎓 学期成绩计算器（加权平均、百分比权重、期末需考多少分）Semester Grade Calculator (Weighted Average, Percentage Weights, Final Exam Needed)
两种用法：输入各项成绩和权重（可以是学分、次数或百分比）求加权平均分并换算等级；或者输入目前的学期成绩、期末考试所占比例和目标总评，算出期末考试至少需要考多少分。本地处理。Two uses: enter each grade with its weight (credits, counts or percentages) for the weighted average and letter grade; or enter your current grade, the weight of the final exam and the grade you want, to see the minimum score you need on the final. Processed locally.
使用说明与常见问题How-to & FAQ
「学期成绩计算器（加权平均、百分比权重、期末需考多少分）」是什么？What is the Semester Grade Calculator (Weighted Average, Percentage Weights, Final Exam Needed) tool?
两种用法：输入各项成绩和权重（可以是学分、次数或百分比）求加权平均分并换算等级；或者输入目前的学期成绩、期末考试所占比例和目标总评，算出期末考试至少需要考多少分。本地处理。Two uses: enter each grade with its weight (credits, counts or percentages) for the weighted average and letter grade; or enter your current grade, the weight of the final exam and the grade you want, to see the minimum score you need on the final. Processed locally.
如何使用「学期成绩计算器（加权平均、百分比权重、期末需考多少分）」？How do I use the Semester Grade Calculator (Weighted Average, Percentage Weights, Final Exam Needed) tool?
在「学期成绩计算器（加权平均、百分比权重、期末需考多少分）」中，填写「用法」、「分数列表」、「权重列表」、「目前成绩 %」、「期末所占比例 %」等参数，结果会随输入实时计算并显示在下方。In the Semester Grade Calculator (Weighted Average, Percentage Weights, Final Exam Needed): Fill in "Use", "Grades", "Weights", "Current grade %", "Final exam weight %"; results are recalculated instantly as you type.
加权平均怎么算？How is a weighted average calculated?
加权平均 = Σ(分数 × 权重) ÷ Σ权重。例如 90 分占 3 学分、70 分占 1 学分：(270 + 70) ÷ 4 = 85。Weighted average = Σ(grade × weight) ÷ Σweights. A 90 worth 3 credits and a 70 worth 1 credit give (270 + 70) ÷ 4 = 85.
期末要考多少分？What do I need on the final?
需要分数 = (目标 − (1 − 期末比例) × 目前成绩) ÷ 期末比例。目前 82 %、期末占 30 %、目标 85 %：(85 − 0.7 × 82) ÷ 0.3 = 92 %。Needed = (target − (1 − final weight) × current) ÷ final weight. With 82 % now, a 30 % final and an 85 % target: (85 − 0.7 × 82) ÷ 0.3 = 92 %.
等级对照是标准吗？Is the letter scale standard?
本页用美国常见的百分制对照（93 以上 A、90 A−、87 B+ ……60 以下 F）。各学校标准不同，请以课程大纲为准。This page uses a common US scale (93+ A, 90 A−, 87 B+ … below 60 F). Schools differ, so check your syllabus.
能举个计算实例吗？Can you show a worked example?
例如在「学期成绩计算器（加权平均、百分比权重、期末需考多少分）」中填 用法 = 加权平均，分数列表 = 80 90，权重列表 = 1 1，结果区显示：加权平均：85；等级（百分制常见对照）：B；简单平均（不计权重）：85；权重合计：2For example, entering Use = Weighted average, Grades = 80 90, Weights = 1 1 in the Semester Grade Calculator (Weighted Average, Percentage Weights, Final Exam Needed) gives: Weighted average: 85; Letter grade (common 100-point scale): B; Simple average (unweighted): 85; Total weight: 2
哪些输入会被检查？Which inputs are validated?
「学期成绩计算器（加权平均、百分比权重、期末需考多少分）」会检查这些输入——「目前成绩 %」、「目标总评 %」：所选方式用到时必须填写；「期末所占比例 %」：所选方式用到时必须填写，须大于 0；绝对值超过 10¹⁵ 的数也会被拒绝。不符合时结果区显示具体提示，不会给出数字。The Semester Grade Calculator (Weighted Average, Percentage Weights, Final Exam Needed) checks its inputs — "Current grade %", "Target grade %": required when the chosen option uses it; "Final exam weight %": required when the chosen option uses it, must be greater than 0; numbers above 10¹⁵ in absolute value are rejected too. When a value fails, the result area names the problem instead of showing a number.
有哪些选项可以调整？What options can I adjust?
「学期成绩计算器（加权平均、百分比权重、期末需考多少分）」的设置：「用法」可选 加权平均、期末需考多少（默认 加权平均）；「分数列表」默认 80 90 70；「权重列表」默认 1 1 1；「目前成绩 %」默认 82；「期末所占比例 %」默认 30；「目标总评 %」默认 85。每次生成结果都按当前设置处理。Settings in the Semester Grade Calculator (Weighted Average, Percentage Weights, Final Exam Needed) — "Use": Weighted average, Final exam needed (default Weighted average); "Grades" default 80 90 70; "Weights" default 1 1 1; "Current grade %" default 82; "Final exam weight %" default 30; "Target grade %" default 85. The result always uses the current settings.
计算精度如何？How precise are the results?
「学期成绩计算器（加权平均、百分比权重、期末需考多少分）」使用 JavaScript 双精度浮点数（约 15–16 位有效数字）；极大或极小的数值可能存在精度误差。The Semester Grade Calculator (Weighted Average, Percentage Weights, Final Exam Needed) uses double-precision floating point (about 15–16 significant digits); very large or very small values may lose precision.
「学期成绩计算器（加权平均、百分比权重、期末需考多少分）」免费吗？需要注册吗？Is the Semester Grade Calculator (Weighted Average, Percentage Weights, Final Exam Needed) free? Do I need an account?
「学期成绩计算器（加权平均、百分比权重、期末需考多少分）」完全免费，无需注册或安装，打开网页即可使用，手机和电脑都能用；输入的内容只在你的浏览器本地处理。The Semester Grade Calculator (Weighted Average, Percentage Weights, Final Exam Needed) is completely free with no sign-up or install and works on phones and desktops; what you enter is processed only in your browser.