单次变更从来不像问题：一个按钮、一版配色、「手机上也能用就行」。问题在于**它们只在加总时才现形**，而多数人从不加总——于是到了第八次，你已经白做了小半个项目，却拿不出一个能发给对方的数字。 把变更记录贴进来，代码做四件事：加总工时并算出它占原约定工时的百分比、区分收过钱的和白做的、按你的真实时薪算出白做部分值多少钱，然后——**用合同金额除以「原工时＋白做工时」，算出你的实际时薪掉到了多少**。最后一个数字是这个工具的重点：它不是观点，是除法，也是最该发给对方看的东西。不是抱怨，是说明为什么下一次变更需要单独计价。 交付日也一并算：新增工时 ÷ 每天可投入小时 = 多少个工作日，跳过周末和**中国法定节假日**（数据来自公开的节假日日历），给出顺延后的具体日期。变更谈判最常见的失败是只谈钱——对方同意加钱，然后默认交付日不变。 $2 解锁可直接发出的正式变更单、三档沟通话术（温和提示→明确报价→暂停开工），以及下一份合同里该补的两句范围定义。No single change looks like a problem: one button, one more colour pass, "just make it work on phones". They only become visible **in aggregate**, and most people never aggregate — so by the eighth request you've given away a third of the project with no number you can send anyone. Paste the log and the code does four things: totals the hours and expresses them as a percentage of the original scope, separates billed from unbilled, values the unbilled work at your real rate, and then — **divides the contract amount by original-plus-unbilled hours to show what your effective rate has fallen to**. That last figure is the point of this tool. It isn't an opinion, it's division, and it's the number worth sending: not a complaint, but the reason the next change gets quoted. The delivery date is computed too: added hours ÷ hours per day = working days, skipping weekends and Chinese public holidays from a public calendar. The most common failure in these conversations is discussing only money — the client agrees to pay and still expects the original date. $2 unlocks a formal change order you can send, three escalation scripts, and the two clauses your next contract is missing.
正式变更单（新增范围／工时／费用／顺延后的交付日，可直接复制发出）+ 三档沟通话术（温和提示 → 明确报价 → 暂停开工提醒）+ 防复发条款（下一份合同里该补的范围定义与变更计价方式）。A formal change order — added scope, hours, fee and the new delivery date, ready to send — three escalation scripts from gentle notice to work-stops-here, and the scope and change-pricing clauses to add to your next contract.
所有计算都基于**你自己填写的**工时估算、合同金额与每日投入，估算不准结果就不准——工时请按「改完并联调完」计，不是纯编码时间。判定档位（≤10%／10-25%／>25%）是本工具给的粗口径参考，不是行业标准或合同依据。顺延日期跳过周末与中国大陆法定节假日（数据来自公开日历，可能滞后或不适用于你所在地区），仅供排期参考，不构成对交付日的承诺。是否属于「超出原范围」最终以你与对方签署的合同条款为准，本工具不提供法律意见；金额较大或已产生争议时请咨询律师。你填写的内容不入库。Every figure derives from **your own** hour estimates, contract amount and daily capacity — estimate badly and the output is wrong. Count hours through integration and rework, not just coding. The bands (≤10% / 10-25% / >25%) are this tool's rough convention, not an industry standard or contractual basis. The projected date skips weekends and mainland-China public holidays from a public calendar that may lag or not apply where you are; it is scheduling guidance, not a commitment. Whether something exceeds the original scope is determined by your signed contract; this is not legal advice. Consult a lawyer where the amounts are significant or a dispute has started. Nothing you enter is stored.