FHA Loan Calculator Guide: How FHA Mortgages Work

The FHA loan is the workhorse of the American mortgage market for first-time and lower-down-payment buyers. Backed by the Federal Housing Administration — and issued by ordinary banks — it lets you put down as little as 3.5%. The trade-off is mandatory mortgage insurance that no conventional loan requires. This guide explains what FHA actually charges, how the insurance math works, and when an FHA loan makes more sense than a conventional one.

What Is an FHA Loan?

An FHA loan is a mortgage insured by the Federal Housing Administration. The FHA doesn't lend money directly — it reimburses the lender if you default. That guarantee lets banks approve borrowers with lower credit scores and smaller down payments than they would for a conventional loan.

Typical FHA requirements:

Minimum down payment: 3.5% with a 580+ credit score; 10% with 500–579.
Minimum credit score: 500 (most lenders overlay a 580 minimum).
Loan limits: vary by county, generally $524,225 to $1,209,750 for a single-family home in 2026.
Property: must be your primary residence (you can own other homes, but the FHA-financed one must be where you live).

The Two Mortgage Insurance Premiums

The big difference from a conventional loan is Mortgage Insurance Premium (MIP) — two separate fees, both charged for the life of most FHA loans:

Upfront MIP (UFMIP): 1.75% of the loan amount, usually rolled into the loan balance. On a $300,000 loan, that's $5,250 added to what you owe.
Annual MIP: 0.55% of the outstanding loan balance per year (for most loans after 2023), paid monthly as part of your mortgage payment. On $300,000, that's about $137/month.

The annual MIP does not go away with equity. On most FHA loans (under 90% loan-to-value, with terms over 15 years), you pay MIP for the full 30 years. The only way to remove it is to refinance into a conventional loan once you have 20%+ equity.

The FHA Payment Formula

Your monthly payment is the same amortization formula as any fixed-rate loan, but the loan amount is higher because UFMIP is rolled in:

Loan Amount = (Home Price − Down Payment) × (1 + 0.0175)

Home Price — purchase price
Down Payment — at least 3.5% of home price
1.75% — upfront MIP, financed into the loan

Then add annual MIP (0.55%/12 of the current balance) to the P&I payment each month.

Worked example: buy a $350,000 home with the minimum 3.5% down ($12,250). The base loan is $337,750. Adding UFMIP: $337,750 × 1.0175 ≈ $343,661. At a 6.5% rate for 30 years:

P&I = 343,661 × [0.005417 × (1.005417)³⁶⁰] / [(1.005417)³⁶⁰ − 1] ≈ $2,176/month

Plus annual MIP: 343,661 × 0.0055 / 12 ≈ $157/month

Total FHA payment: ~$2,333/month

Now compare to a conventional 5%-down loan on the same home, with no MIP but with private mortgage insurance (PMI) that drops off at 78% LTV:

FHA Conventional (5% down)

Loan amount $343,661 (incl UFMIP) $332,500

P&I at 6.5% $2,176 $2,107

Mortgage insurance $157/mo (forever) $138/mo initially; drops at 78% LTV

Total monthly $2,333 $2,245 → falls to $2,107 around year 8

Total interest over 30 yrs $495,408 $445,320 (less because smaller loan)

When FHA Wins (and When It Doesn't)

FHA isn't always the right choice. Three decision rules:

FHA wins if you have less than 10% down, your credit score is below 720, and you expect to move or refinance within 5–7 years.

Conventional wins if you can put 10%+ down and your credit is 740+. Better rates, no upfront MIP, PMI eventually drops off.

Don't use FHA if you're buying a multi-unit property you intend to rent out, or you can afford 20%+ down — FHA's loan limits cap its usefulness for expensive markets.

💡 Refinancing out of FHA

Many FHA borrowers plan to refinance into a conventional loan once they hit 20% equity. The math: you'd skip ~$150/month of MIP forever, which on a $300,000 loan saves roughly $50,000 over the remaining term. Worth running the numbers before year 5.

Try It

Use the FHA Loan Calculator to:

Model your monthly payment with the 3.5% minimum down and see how much of it is MIP.

Compare the total cost of FHA vs a conventional loan with PMI at different down-payment levels.

Estimate when you'd reach 20% equity — the point at which refinancing into a conventional loan makes sense.

The calculator uses the current FHA annual MIP rate (0.55% for most post-2023 loans) and rolls in the 1.75% upfront MIP automatically.

	FHA	Conventional (5% down)
Loan amount	$343,661 (incl UFMIP)	$332,500
P&I at 6.5%	$2,176	$2,107
Mortgage insurance	$157/mo (forever)	$138/mo initially; drops at 78% LTV
Total monthly	$2,333	$2,245 → falls to $2,107 around year 8
Total interest over 30 yrs	$495,408	$445,320 (less because smaller loan)

FHA 贷款是美国首套房和低首付购房市场的主力。它由联邦住房管理局背书、普通银行发放——让你最低只需 3.5% 首付。代价是任何传统贷款都没有的强制房贷保险。本文解释 FHA 实际收取的费用、保险数学、以及何时 FHA 比传统贷款更划算。

什么是 FHA 贷款？

FHA 贷款是由联邦住房管理局保险的抵押贷款。FHA 自己不放款——而是如果你违约，它会补偿银行。这份担保让银行愿意批准比传统贷款更低信用分、更低首付的借款人。

FHA 典型要求：

最低首付：信用分 580+ 时 3.5%；500–579 时 10%。
最低信用分：500(大多数银行加 580 隐形门槛)。
贷款上限：按县不同，2026 年单户住宅一般 $524,225 到 $1,209,750。
房产：必须是你主要住所(你可以拥有其他房子，但 FHA 贷款这套必须自住)。

两笔房贷保险费

与传统贷款最大的不同是房贷保险费(MIP)——两笔独立费用，多数 FHA 贷款要交一辈子：

首笔 MIP(UFMIP)：贷款金额的 1.75%，通常加到贷款本金。$300,000 贷款就是多欠 $5,250。
年度 MIP：每年未偿还余额的 0.55%(2023 后大多数贷款)，按月支付，计入月供。$300,000 贷款大约 $137/月。

年度 MIP 不会随权益增加而消失。对大多数 FHA 贷款(LTV 90% 以下、期限超过 15 年)，30 年里都要交。唯一免掉的方法是再融资到传统贷款(权益达 20%+)。

FHA 月供公式

月供与任何固定利率贷款相同，但贷款金额更高(UFMIP 算进去)：

贷款金额 = (房价 − 首付) × (1 + 0.0175)

然后把年度 MIP(月率 0.55%/12 × 当前余额)每月加到 P&I 上。

举例：买 $350,000 房子，最低 3.5% 首付($12,250)。基础贷款 $337,750。加 UFMIP 后：$343,661。6.5% 利率、30 年：

P&I = 343,661 × ... ≈ $2,176/月
加年度 MIP ≈ $157/月
FHA 总月供 ~$2,333/月

对比同样房子、传统贷款、5% 首付、无 MIP 但有 PMI(LTV 78% 时取消)：

	FHA	传统(5% 首付)
贷款金额	$343,661(含 UFMIP)	$332,500
6.5% 下 P&I	$2,176	$2,107
房贷保险	$157/月(终身)	$138/月起；78% LTV 后取消
月供总计	$2,333	$2,245 → 第 8 年降至 $2,107
30 年总利息	$495,408	$445,320(贷款更小)

何时 FHA 更划算

FHA 不总是最优。三个决策规则：

FHA 更划算：首付低于 10%、信用分低于 720、计划 5–7 年内搬家或再融资。
传统更划算：能付 10%+ 首付、信用分 740+。利率更低、无首笔 MIP、PMI 最终会取消。
不要选 FHA：买多户型准备出租；或能付 20%+ 首付——FHA 上限在高价市场反而局限。

💡 再融资退出 FHA

很多 FHA 借款人计划权益达 20% 时再融资到传统贷款。数学上：跳过一辈子 ~$150/月 MIP，$300,000 贷款剩余期能省约 $50,000。第 5 年前值得算算。

动手试试

用 FHA 贷款计算器：

用 3.5% 最低首付算月供，看其中多少是 MIP。
不同首付水平下比较 FHA 与传统贷款的总成本。
估算何时达到 20% 权益——那是再融资到传统贷款的转折点。

计算器使用当前 FHA 年度 MIP 利率(2023 后多数贷款 0.55%)并自动加 1.75% 首笔 MIP。

FHA Loan Calculator Guide: How FHA Mortgages WorkFHA 贷款计算器指南：联邦住房管理局贷款如何运作