住宅ローン計算機
月々の住宅ローン返済額と償還スケジュールを計算
使い方
値を入力
入力フィールドに数値やパラメータを入力します。
即座に結果を取得
入力するとすぐに結果が更新されます — 送信ボタンは不要です。
コピーまたは保存
結果をクリップボードにコピーするか、ワークフローで活用します。
このツールを使う理由
完全無料
隠れたコストもプレミアムプランもありません — すべての機能が無料です。
インストール不要
すべてブラウザで実行されます。ソフトウェアのダウンロードやインストールは不要です。
プライベート＆安全
データはデバイスの外に出ることはありません。サーバーにアップロードされることはありません。
モバイル対応
完全レスポンシブ対応 — スマートフォン、タブレット、デスクトップで利用できます。
A mortgage is one of the largest financial commitments most people make. Understanding how mortgage payments work helps you choose the right loan and save thousands over its lifetime.
Key Concepts
Amortization
Early payments go mostly toward interest, with the principal portion growing over time. Understanding this schedule helps you see the true cost of your loan.
Down Payment
A larger down payment reduces your loan amount, lowers monthly payments, and may help you avoid private mortgage insurance (PMI), typically required when paying less than 20% down.
Fixed vs. Variable Rate
Fixed-rate mortgages lock in your interest rate for the full term, offering predictability. Variable-rate mortgages may start lower but can fluctuate with the market.
Loan Term
Shorter terms (e.g. 15 years) have higher monthly payments but cost significantly less in total interest compared to longer terms (e.g. 30 years).
Practical Tips
Keep your total housing costs (mortgage, taxes, insurance) below 28% of your gross monthly income.
Compare offers from multiple lenders — even a 0.25% rate difference can save tens of thousands over the life of the loan.
Consider making extra payments toward principal when possible to shorten your loan term and reduce total interest.
Factor in closing costs, property taxes, insurance, and maintenance when budgeting for a home — the mortgage payment is only part of the total cost.
This content is for educational purposes only and does not constitute financial advice. Consult a qualified financial advisor or mortgage professional before making borrowing decisions.