The Boise boom explained. Idaho's 5.8% flat tax (converted from progressive in 2022) competes with California's 13.3% top rate. Counter-intuitive finding: California's progressive brackets mean lower earners may pay LESS in CA than Idaho's flat rate. At $100,000: California $5,762 vs Idaho $5,800—California is actually $38 cheaper! High earners ($250K+) see significant Idaho savings. Boise's explosive growth (fastest-growing 2010-2020) makes this comparison increasingly relevant.

By CountryTaxCalc Research Team

Last Updated: April 2026

The Big Picture

🌴 California

13.3%

Highest Income Tax

10 brackets up to 13.3%

🥔 Idaho

5.8%

Flat Tax

Changed to flat 5.8% in 2022

Typical Annual Savings

At $100,000 income:

-$38

That is CA saves $3/month (!) back in your pocket!

Tax Savings by Income Level

IncomeCA TaxID TaxSavings10-Year
$50,000 $2,172$2,900CA saves $728$7,280
$75,000 $3,765$4,350CA saves $585$5,850
$100,000 $5,762$5,800CA saves $38$380
$150,000 $10,438$8,700ID saves $1,738$17,380
$250,000 $20,663$14,500ID saves $6,163$61,630
$500,000 $50,413$29,000ID saves $21,413$214,130

California Pros and Cons

✅ Pros

  • Lower effective tax for incomes under $110K (!)
  • Massive job market: tech, entertainment, biotech
  • Year-round mild weather (Southern CA)
  • Cultural diversity and amenities

❌ Cons

  • 13.3% top rate crushes high earners
  • Housing crisis: median $750K+ in metros
  • Traffic, wildfires, drought increasingly severe
  • High cost of living across all categories

Idaho Pros and Cons

✅ Pros

  • 5.8% flat tax benefits high earners
  • Boise boom: Micron $15B investment, tech growth
  • Affordable housing: Boise median ~$480K (up from $250K)
  • Outdoor lifestyle: skiing, hiking, fishing

❌ Cons

  • Higher effective tax than CA for incomes under $110K
  • Small job market compared to CA metros
  • Cold winters (especially northern ID)
  • Housing prices rising fast (Boise +91% 2015-2022)
💡

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Frequently Asked Questions

Q: Wait—California is actually cheaper than Idaho for taxes?

At certain income levels, yes! California's progressive brackets start at 1% for low incomes, while Idaho's 5.8% flat rate applies to ALL income. At $50K: CA $2,172 vs ID $2,900—CA saves $728. At $100K: nearly identical ($38 difference). The crossover point is around $110K—above that, Idaho's flat rate wins. This surprises many people who assume CA is always more expensive.

Q: At what income does Idaho become cheaper than California?

The crossover is approximately $110,000 in taxable income. Below that, California's progressive brackets (starting at 1%) beat Idaho's 5.8% flat rate. Above $110K, Idaho wins—and the gap widens dramatically at higher incomes. At $250K: ID saves $6,163/year. At $500K: ID saves $21,413/year. High earners benefit most from Idaho's flat tax.

Q: Is the Boise housing market still affordable?

Relatively, but it's changed dramatically. Boise median home price: $480K (2026), up from $250K in 2019—a 92% increase in 7 years, driven by California migration. Still cheaper than Bay Area ($1.3M+) or LA ($850K+), but no longer the bargain it was. California refugees priced out many locals. Nampa, Meridian, and smaller towns remain more affordable.

Q: Is Idaho's tech scene big enough for Bay Area workers?

Growing but still small. Micron (memory chips) is Idaho's tech anchor with a $15B expansion. HP, Clearwater Analytics, and Albertsons HQ are there. But Boise has a tiny fraction of Bay Area jobs—most CA→ID moves involve remote work, keeping Bay Area salaries while living in Boise. That's the optimal strategy: CA salary + ID 5.8% tax + lower housing.

Q: What about Idaho vs other no-tax states like Texas or Nevada?

Idaho's 5.8% flat rate is higher than Texas (0%), Nevada (0%), or Washington (0%). If pure tax savings is the goal, those states win. But Idaho offers outdoor lifestyle closer to Pacific Northwest culture, and Boise is seeing tech growth those states' secondary cities lack. For Californians wanting mountains + tech jobs + modest tax savings, Idaho is the compromise choice.

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