Property Tax Calculator – Assessed, Rate & Monthly Estimator

Why Property Tax in Texas Looks Nothing Like California Prop 13?

Texas has no income tax but property tax averages 1.8% of market value. On a $400,000 home that is $7,200 per year $600 per month. California has income tax but Prop 13 caps assessed increase at 2% per year until sale, so average effective rate shows 0.75% even though statutory rate is about 1% plus local bonds. Same $400,000 home in California assessed may be $400,000 if just bought, tax $3,000 per year $250 per month, but if owned 10 years assessed might be $487,000 market $600,000 but assessed only $475,000 due to cap, effective 0.62% on market.

New Jersey highest effective about 2.2% — $400,000 home $8,800 per year $733 per month. Hawaii lowest about 0.28% — $400,000 home $1,120 per year $93 per month. Florida about 1.1% average $400,000 $4,400 per year $367 per month but homestead exemption up to $50,000 lowers it. This calculator uses market value times assessment ratio minus exemptions times rate to show annual and monthly, not just value times rate.

How To Use This Property Tax Tool — 4 Quick Steps

Step 1 — Enter market home value. Example $400,000 current market price, not assessed. Use Zillow or county market estimate.

Step 2 — Set assessment ratio and exemptions. Ratio example 100% means county taxes 100% of market, 80% means $400k market = $320k assessed before exemptions. Exemptions example $0 no homestead, $25,000 Florida homestead, $100,000 California senior? Enter amount that reduces assessed.

Step 3 — Choose tax rate. Rate example 0.75% California Prop 13 average, 1.8% Texas average, 2.2% New Jersey highest, 0.28% Hawaii lowest, 1.1% Florida. Select or enter custom. This is effective rate per county, not statutory.

Step 4 — Calculate. Hit Calculate Property Tax. See assessed value = market×ratio% - exemptions, annual tax = assessed×rate%, monthly = annual/12, effective = annual/market, per $100k = rate×100k. Change ratio from 100% to 80% and see assessed drop $80,000 and annual drop $600 at 0.75% rate.

How It Calculates — Formula & Methodology

Source: County tax assessors, Census, Tax Foundation effective rates. Prop 13 California Constitution Article 13A caps assessed increase 2% per year.

Assessed = Market × (Ratio% /100) - Exemptions
Assessed Taxable = Max(0, Assessed)
Annual Tax = Assessed Taxable × (Rate% /100)
Monthly Tax = Annual Tax /12
Effective Rate = Annual Tax / Market ×100
Per $100k = Rate% × $100,000

Verification with $400,000 market 100% ratio $0 exemption:

• California 0.75%: Assessed $400,000, Annual $400,000×0.75%=$3,000, Monthly $250, Effective 0.75%, Per $100k $750
• Texas 1.8%: Assessed $400,000, Annual $400,000×1.8%=$7,200, Monthly $600, Effective 1.8%, Per $100k $1,800
• New Jersey 2.2%: Assessed $400,000, Annual $8,800, Monthly $733.33, Effective 2.2%, Per $100k $2,200
• Hawaii 0.28%: Assessed $400,000, Annual $1,120, Monthly $93.33, Effective 0.28%, Per $100k $280
• With 80% ratio $400k market 80% = $320k assessed minus $25k homestead = $295k taxable ×1.1% Florida = $3,245 annual $270.42 monthly

Guards: assessed floor 0, ratio 10-100 capped, exemptions floor 0, rate 0-5 capped, non-finite→0.

What Results Mean — Only Necessary Details

Assessed Value: Market times ratio minus exemptions. Example $400k×100% - $0 = $400k assessed taxable. This is what county taxes.

Annual Tax: Assessed times rate. Example $400k×0.75%=$3,000 annual. County bill annual but often split in two installments.

Monthly Tax: Annual divided by 12 for escrow. Example $3,000/12=$250 per month added to mortgage PITI.

Effective Rate: Annual divided by market times 100. Shows true percent on market. Example $3,000/$400k=0.75% effective, matches rate if 100% ratio no exemptions.

Per $100k Value: Rate times $100,000. Quick comparison. Example 1.8% Texas = $1,800 per $100k value, 0.75% California = $750 per $100k.

Example — Texas No Income Tax vs California Prop 13 vs Florida Homestead

Base: $400,000 market 100% ratio $0 exemption California 0.75% → Assessed $400k Annual $3,000 Monthly $250 Effective 0.75% Per $100k $750.

Texas 1.8% same $400k: Assessed $400k Annual $7,200 Monthly $600 Effective 1.8% — $4,200 more per year than California $350 more per month due to rate and no Prop 13 cap, trade-off for no income tax.

Florida 1.1% with $25k homestead exemption: Market $400k ratio 100% = $400k - $25k = $375k assessed ×1.1%=$4,125 annual $343.75 monthly — $1,125 more than California but homestead saves $275 vs no exemption $4,400.

New Jersey 2.2% highest: $400k×2.2%=$8,800 annual $733.33 monthly — $5,800 more than California annual, shows why NJ property tax is major budget item.

Hawaii 0.28% lowest: $400k×0.28%=$1,120 annual $93.33 monthly — lowest due to high home values but low rate, but other taxes high.

80% ratio example: $400k market 80% ratio = $320k assessed - $0 exemption = $320k ×0.75%=$2,400 annual $200 monthly — ratio reduces tax $600 vs 100% ratio.

Common Mistakes

1. Using market value directly without ratio: Some counties assess 80% of market, not 100%. Using $400k market at 80% ratio = $320k assessed $80k less, tax $600 less at 0.75% rate.
2. Forgetting homestead exemption: Florida $25k to $50k homestead reduces assessed $25k saves $275 at 1.1% rate. California homeowner exemption $7,000 saves $52.50 at 0.75%.
3. Mixing Prop 13 assessed with market: California assessed capped 2% yearly increase, market may rise 10%. Effective rate on market looks low 0.62% but statutory 1% plus bonds on assessed. Use assessed from tax bill, not Zestimate, for exact.
4. Assuming rate is same everywhere: Texas 1.8% average but county varies 1.6% to 2.2% plus school district. New Jersey 2.2% average but some counties 2.5%. Use your county effective rate from Tax Foundation or assessor.
5. Forgetting monthly escrow: Annual $3,000 = $250 per month escrow added to PITI. If you pay $2,000 PITI mortgage $1,500 principal interest $250 tax $250 insurance, tax is 12.5% of PITI — budget accordingly.

Practical Tip

Check your county assessor site for exact assessed value and exemptions — market Zestimate is not assessed. Apply for homestead exemption immediately after purchase — Florida up to $50k, Texas 20% plus $100k school, California $7k homeowner. If you are in California, Prop 13 base year value transfers for seniors over 55 per Prop 19 can keep low assessed when moving. Compare effective rate not just rate — Texas 1.8% on $400k $7,200 vs California 0.75% $3,000 difference $4,200 per year $350 per month can offset income tax savings if moving from Texas to California.

Important Limitations

This tool provides estimates for educational purposes only. Not tax, financial, or legal advice. Results depend on inputs you provide. Assessment ratios, exemptions, tax rates, caps like Prop 13 2%, and local bonds, Mello-Roos, school levies vary by state, county, city and period. Does not include special assessments, HOA, insurance, or additional local districts. Verify with your county tax assessor, tax bill and local tax authority. Inputs are processed in your browser and not sent to a server for this calculator component.

Frequently Asked Questions

How is property tax calculated?

Property tax = assessed value times tax rate. Assessed = market value times assessment ratio minus exemptions like homestead. Example $400k market 100% ratio $0 exemption 0.75% rate = $3,000 annual $250 monthly.

What is assessment ratio?

Assessment ratio is percent of market value that county taxes. Many states 100%, some 80% or lower. Example $400k market 80% ratio = $320k assessed before exemptions.

Why does California Prop 13 matter?

California Prop 13 caps assessed increase 2% per year until sale. So market may rise 10% but assessed only 2%, effective rate looks lower like 0.75% average vs Texas 1.8% with no cap.

Which states have highest and lowest property tax?

Highest effective rates New Jersey about 2.2%, Illinois 2.08%, Texas 1.8% trade-off for no income tax. Lowest Hawaii 0.28%, Alabama 0.40%, Colorado 0.48% due to assessment limits and lower rates.

What are exemptions?

Exemptions reduce assessed value before rate. Homestead exemption example $25k to $100k for primary residence. Example $400k assessed minus $25k homestead = $375k taxable.

Is property tax monthly or annual?

County bills annual but mortgage escrow divides by 12 monthly. Annual $3,000 = $250 per month escrow.

Does this calculator save data?

No. Calculation runs in your browser. Inputs are not sent to a server for this calculator component. Closing tab clears values.