Estimate income-based taxes & payment instalments for freelancers worldwide
Freelancing often means you are your own payroll department. Nobody withholds tax for you, so you must estimate what you owe, set money aside and pay it on the right dates. This estimator models income tax, self-employment or social contributions and instalment schedules for several countries, so you can see your likely annual liability and how much to keep in reserve.
Enter your net self-employment profit, any other income and the amount you have already paid. The tool then applies the relevant progressive income-tax brackets, adds self-employment or social-security contributions, subtracts the deduction for employer-equivalent contributions where the rules allow, and reports a total liability plus a quarterly payment plan.
The core is a progressive tax function applied to taxable income:
For the United States, self-employment tax is charged on 92.35% of net profit, then split into Social Security and Medicare:
Half of that self-employment tax is deductible, and the remaining taxable income is reduced by the standard or itemized deduction before the brackets are applied.
Suppose net self-employment profit is $60,000 with the 2025 defaults. Self-employment earnings are 60,000 × 0.9235 = $55,410, giving roughly $6,871 of Social Security and $1,607 of Medicare, or about $8,478. Half of that ($4,239) is deductible; after the $15,000 standard deduction, taxable income is $40,761, producing about $4,653 of federal income tax. Combined liability is therefore about $13,131, and the safe-harbour target is 90% of it.
| Item | Amount |
|---|---|
| Net profit | $60,000 |
| Self-employment tax | ≈ $8,478 |
| Federal income tax | ≈ $4,653 |
| Estimated total | ≈ $13,131 |
The most common error is spending the whole profit and then struggling when the quarterly deadline arrives. Reserve 25–30% of every payment and review the estimate whenever income changes. Remember that advance-payment rules differ between countries: the UK uses 50% Payments on Account, Canada exempts instalments below C$3,000, and pension or retirement contributions may reduce the taxable base. Treat the output as a planning figure, not a filed return.
自由职业意味着自己就是自己的"发薪部门"：没有人替你代扣税款，你必须自己估算全年应缴税额、预留资金并在正确的日期缴款。本工具为多个国家建模，涵盖累进所得税、自雇税或社保缴款以及分期预缴计划，帮助你了解全年大致税负以及需要预留多少现金。
输入自雇净收入（利润）、其他收入以及已经缴纳的金额，工具会套用相应的累进所得税率表，加上自雇税或社会保障缴款，在规则允许时扣除雇主对等缴款部分，并给出总税负与季度缴款计划。
核心是把累进税率应用到可税收入上：
以美国为例，自雇税按净利润的 92.35% 计征，再拆分为社会保障税与医疗保险税：
其中自雇税的一半可以扣除，剩余可税收入再减去标准扣除或分项扣除，然后才套用税率档次。
假设自雇净利润为 60,000 美元，使用 2025 默认参数。自雇计税基数 = 60,000 × 0.9235 = 55,410 美元，社会保障税约 6,871 美元，医疗保险税约 1,607 美元，合计约 8,478 美元。其一半（约 4,239 美元）可扣除；再减去 15,000 美元标准扣除后，可税收入为 40,761 美元，对应联邦所得税约 4,653 美元。全年合计税负约 13,131 美元，安全港目标为其中的 90%。
| 项目 | 金额 |
|---|---|
| 净利润 | $60,000 |
| 自雇税 | ≈ $8,478 |
| 联邦所得税 | ≈ $4,653 |
| 预估总额 | ≈ $13,131 |
最常见的错误是把手里的利润全部花掉，等到季度截止日才发现缴不出税。建议每笔收入预留 25%–30%，并在收入变化时重新估算。要注意各国的预缴规则差异很大：英国采用 50% 的账户预付款，加拿大净欠税低于 3,000 加元可免分期，养老金或退休账户缴款可能降低计税基数。请把结果当作规划参考，而不是最终申报表。
In most countries with self-employment taxes, yes. The US (1040-ES), UK (Payments on Account), Canada, Australia, Japan and New Zealand all use instalment payment systems.
A common rule of thumb is 25–30% of net income, but it varies by country and tax bracket. This tool estimates your specific liability.
Underpayment can trigger interest and penalties, though most countries provide a safe harbor (such as 90% of the current year or 100% of the prior year) that avoids them.