HarborPlain

Money

From the true first-year cost of a baby to choosing between a 529 and a UTMA, the money choices you make now compound for eighteen years. We turn each one into a clear number and a simple next step.

Tools

Baby Cost Calculator

Estimate your baby's first-year cost: adjust eight categories, compare feeding and childcare scenarios, and see the monthly figure.

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Nanny Tax Calculator

Nanny vs daycare

The true cost of a nanny: Social Security, Medicare, FUTA, and state unemployment taxes on top of wages, then a nanny vs daycare comparison that flips with the number of children.

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529 vs UTMA Comparator

Project what a 529 plan and an UTMA account would each be worth at 18, and see how they differ on taxes, control, and financial aid.

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Custodial Roth IRA Calculator

Retirement

See what a working child's custodial Roth IRA could grow to by retirement: small early contributions, capped at earned income, compounding tax-free for decades.

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529 State Tax-Deduction Optimizer

By state

Pick your state and see the state income-tax you'd save on a 529 contribution: deduction or credit, per-beneficiary caps, parity, owner-only, and April deadlines. All 50 states + DC.

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Kiddie Tax Calculator

UTMA tax

Estimate the tax on a child's unearned income: the tax-free tier, the child's rate, and the amount taxed at the parent's rate. The UTMA's main drawback, quantified.

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College Savings Goal Calculator

Set a college-cost target and see the monthly saving required to hit it, with college inflation and growth on what you already have.

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HSA Contribution Limit Calculator

Prorate your HSA limit for a mid-year start: the safe sum-of-months figure and the full-year last-month rule side by side, with the testing-period trap and 55+ catch-up. 2025 & 2026 IRS limits.

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Guides

Money

Is a Dependent Care FSA Worth It for Two Incomes?

Is a dependent care FSA worth it for two incomes? The break-even math, what it saves at different tax brackets, and why dual-income families rarely forfeit it.

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Money

How Much to Save Before Baby Is Born: A Pre-Birth Money Target

How much to save before baby is born, broken into four targets: the delivery bill, the unpaid-leave income gap, a bigger emergency fund, and up-front gear.

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Money

Dependent Care FSA vs Child Tax Credit: Which, and Can You Use Both?

Dependent care FSA vs child tax credit, untangled: what each one does, the credit that actually competes with a DCFSA, and how to coordinate all three in 2026.

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Money

529 Plan vs Savings Account for College: Which Grows More?

529 plan vs savings account for college, compared on taxes, financial aid, flexibility, and 18-year growth, so you can pick the right vehicle (or use both).

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Money

Can You Use a 529 Plan for K-12 Tuition? The 2026 Rules

Can you use a 529 plan for K-12 tuition? Yes, up to $20,000 per year in 2026 under new federal rules, but state tax conformity and compounding trade-offs matter.

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Money

UTMA vs 529 for Grandparents: Which Gift Is Better?

UTMA vs 529 for grandparents in 2026: how each affects financial aid, taxes, control, and gifting, plus the FAFSA change that reshaped the grandparent 529.

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Money

HSA vs FSA for New Parents: Which One Fits a Baby Year?

HSA vs FSA for new parents in 2026: how the three accounts differ, which you can hold together, the childcare FSA jump to $7,500, and how to choose for a baby year.

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Money

529 Plan for a Newborn: Where to Start

How to start a 529 plan for a newborn: opening before the SSN arrives, picking the right state plan, how much to begin with, and what the money can pay for.

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Money

Does Having a Baby Increase My HSA Contribution Limit?

Having a baby can raise your HSA contribution limit by moving you to family coverage. Here is how the mid-year proration and last-month rule really work.

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The money decisions that matter most

A baby changes a household budget in two ways: a first year that commonly runs into five figures, where childcare is usually the largest line by far, and a set of long-horizon choices that reward starting early. Neither requires perfect planning; both reward knowing the real numbers instead of guessing.

The first-year question is about cash flow: what you will actually spend on delivery, gear, diapers, feeding, childcare, and health coverage, and which of those lines your own choices move. The long-horizon question is about compounding: a college fund opened in the first year has eighteen years to grow, and the account type you pick, a 529 plan or a custodial UTMA, changes the taxes, the control, and the financial-aid treatment of every dollar in it.

Our calculators put your own numbers on both questions, and every default is anchored to a primary source you can check.