How Much Does It Cost to Run LLMs Locally?

📚 More on this topic: Budget AI PC Under $500 · GPU Buying Guide · Local LLMs vs ChatGPT · Best Used GPUs 2026 · Planning Tool

Running LLMs locally has real costs — hardware, electricity, and your time. But so do cloud APIs and subscriptions. The question is: when does local AI actually save money?

This guide breaks down every cost involved and shows you exactly when running your own models beats paying for cloud services.

Update, 2026-10-02: the summary of this page originally said $200-800 for hardware and a 3-6 month payback against ChatGPT Plus, and called a $750 RTX 3090 setup a permanent replacement for the subscription. At September 2026 used prices the hardware is about $300-1,700, a used RTX 3060 setup pays back in roughly 17-25 months, and a 3090 setup takes 7-12 years. Every table below is recomputed and dated.

The Cost Categories

One-Time Costs (Hardware)

• GPU
• CPU (if upgrading)
• RAM (if upgrading)
• Power supply (if upgrading)
• Storage (if upgrading)

Ongoing Costs (Electricity)

• GPU power draw during inference
• System idle power
• Cooling (included in GPU draw)

Hidden Costs

• Your time setting up
• Troubleshooting
• Model quality differences

Hardware Costs: What You Actually Need

Budget Setup ($325-405)

Update, 2026-10-02: this table originally said $180 for the RTX 3060, $30 for the RAM and $210 in total. The card is $275-325 as of September 2026 (107 sold eBay listings), and the RAM line now uses our store’s DDR4 band ($50-80 for 16GB, last priced March 2026), so the setup is $325-405.

If your existing PC has a 500W+ PSU and a modern CPU (anything from last 8 years), add a used RTX 3060 12GB and you’re running local AI.

What you can run:

• Llama 3.1 8B at ~40 tok/s
• Qwen 2.5 14B at ~20 tok/s
• Stable Diffusion XL
• Whisper speech-to-text

Mid-Range Setup ($1,300-1,670)

The RTX 3090 setup handles everything except the largest 70B models at good quality.

What you can run:

• Qwen 2.5 32B at ~40 tok/s
• DeepSeek R1 Distill 32B at ~35 tok/s
• Llama 3.3 70B at ~15 tok/s (with offloading)
• Flux image generation at full quality

High-End Setup ($3,045-3,610)

Update, 2026-10-02: this table originally said $1,600 for the RTX 4090, $150 for the RAM and $1,900 in total. The card is $2,575-3,010 used as of October 2026 (median $2,860, from 216 sold eBay listings); the RAM line uses our store’s DDR5 band ($320-450 for 64GB, March 2026). The setup is $3,045-3,610.

The RTX 4090 runs everything the 3090 can, but 30-50% faster.

Complete New Build ($420-520)

If you need an entire computer, see our Budget AI PC Under $500 guide:

Update, 2026-10-02: this build originally said $180 for the RTX 3060, $500 in total. It now mirrors the parts list in our budget build guide: a used Optiplex tower ($100-150), the RTX 3060 at $275-325 (September 2026), and a 500W PSU if needed ($45). That is $420-520, about $475 at the medians.

Electricity Costs: The Ongoing Expense

Power Draw by GPU

System overhead: Add ~100W for CPU, RAM, drives, etc.

Monthly Cost Calculation

Formula:

Monthly cost = (GPU watts + system watts) × hours/day × 30 days × electricity rate ÷ 1000

Example: RTX 3090, 3 hours daily use, $0.15/kWh

(350W + 100W) × 3 hours × 30 days × $0.15 ÷ 1000 = $6.08/month

Monthly Cost Table

Based on $0.15/kWh US average. Adjust for your local rate.

Real-World Usage Patterns

Light use (research, occasional questions): 1 hour/day

• RTX 3060: ~$1/month
• RTX 3090: ~$2/month

Moderate use (daily coding assistant): 3 hours/day

• RTX 3060: ~$4/month
• RTX 3090: ~$6/month

Heavy use (all-day development, content creation): 8 hours/day

• RTX 3060: ~$10/month
• RTX 3090: ~$16/month

Cloud API Costs: What You’re Comparing Against

Subscription Services

Pay-Per-Token APIs

What Does Usage Actually Cost?

Average conversation: ~2,000 tokens total (input + output)

Coding session: ~50,000 tokens (lots of code context)

Break-Even Analysis: When Local Pays Off

vs ChatGPT Plus ($20/month)

Update, 2026-10-02: this table originally said $200, $500 and $750 with break-evens of 13, 31 and 54 months. At September 2026 prices (3060 $275-325, 3090 $1,200-1,400 as of August) and the $420-520 build above, the break-evens are 17-20, 26-33 and 86-100 months.

But consider:

• ChatGPT Plus has usage limits
• Local has no limits — run 24/7 if you want
• Local works offline
• No data leaves your machine

vs OpenAI API (Heavy User)

A developer using 2M tokens/day on GPT-4o:

• API cost: ~$25/day = $750/month

Break-even for a $1,300-1,670 RTX 3090 setup: about 2 months

Even using cheaper GPT-4o mini at 2M tokens/day:

• API cost: ~$1.50/day = $45/month

Break-even: ~29-37 months

Update, 2026-10-02: these two break-evens originally said 1 month and ~17 months for a $750 setup. The 3090 setup is $1,300-1,670 as of September 2026, so they are about 2 months and ~29-37 months.

vs Claude Pro ($20/month)

Same math as ChatGPT Plus. The question is whether local models meet your quality needs.

Local models that compete:

• Qwen 2.5 32B — comparable to GPT-4o mini for many tasks
• DeepSeek R1 Distill 32B — strong reasoning
• Llama 3.3 70B — approaches GPT-4 quality

The Real Cost Comparison

Total Cost of Ownership (3 Years)

Assumes moderate use (3 hrs/day)

Update, 2026-10-02: the setup rows originally said $260 / $356 and $822 / $966, built on a $210 3060 setup and a $750 3090. At September 2026 prices (the $325-405 budget setup above, and a $1,200-1,400 3090 as of August) they are $373-453 / $469-549 and $1,272-1,472 / $1,416-1,616. Over three years the 3060 setup still costs less than ChatGPT Plus ($469-549 against $720), and the 3090 setup costs about twice as much.

Break-Even Chart

ChatGPT Plus cumulative cost:
Month 1:  $20   Month 6:  $120   Month 12: $240
Month 18: $360  Month 24: $480   Month 36: $720

RTX 3060 setup ($300 + $4/month):
Month 1:  $304  Month 6:  $324   Month 12: $348
Month 18: $372  Month 24: $396   Month 36: $444

Break-even: ~19 months
Savings after 3 years: $276

Update, 2026-10-02: this chart originally said $200 for the 3060, a ~13-month break-even and $376 saved over three years. It now uses the card’s $300 median as of September 2026: break-even at about 19 months, $276 saved over three years.

Hidden Costs: What the Math Doesn’t Show

Setup Time

First-time setup: 2-8 hours

• Installing drivers, CUDA, Ollama
• Downloading models
• Troubleshooting if something breaks

Value of your time: If you bill $50/hour, 4 hours of setup = $200

Quality Differences

Local models in 2026 are good, but not always GPT-4/Claude-level:

For most tasks, local models are good enough. For cutting-edge capabilities, you may still need cloud APIs occasionally.

Reliability

• Cloud APIs: 99.9% uptime, always updated
• Local: Your hardware, your problem

Budget $0-50/year for potential repairs or troubleshooting.

When Local AI Makes Financial Sense

Strong Yes

• Heavy daily use — 4+ hours/day of LLM interaction
• API-heavy development — would spend $50+/month on tokens
• Privacy requirements — data can’t leave your machine
• Offline needs — travel, unreliable internet
• Already have hardware — gaming PC with decent GPU

Maybe

• Moderate use — 1-2 hours/day (break-even takes longer)
• Need cutting-edge models — may still need cloud API access
• Tight budget — upfront cost is significant

Probably Not

• Light occasional use — free tiers of ChatGPT/Claude are enough
• Always need latest models — local lags behind cloud
• Zero technical tolerance — setup requires some effort

Cost-Optimized Builds

The $275-405 AI Upgrade

Already have a PC with 500W+ PSU:

Break-even vs ChatGPT Plus: ~17-25 months

Update, 2026-10-02: this build originally said $180 for the RTX 3060, $180-210 in total and a ~12-month break-even. The card is $275-325 as of September 2026 (RAM at our store’s March DDR4 band), so it is $275-405 and about 17-25 months. Runs: 7B-14B models, Stable Diffusion

The $420-520 Complete Build

Need an entire computer:

Break-even vs ChatGPT Plus: ~26-33 months

Update, 2026-10-02: this build originally said $180 for the RTX 3060, $500 in total and a ~31-month break-even. It now mirrors the parts list in our budget build guide: a used Optiplex tower ($100-150), the RTX 3060 at $275-325 (September 2026), and a 500W PSU if needed ($45). That is $420-520, about $475 at the medians, and the break-even is about 26-33 months. Runs: 7B-14B models, Stable Diffusion

The $1,300-1,500 Power Build

Want to run 32B models:

Update, 2026-10-02: this build originally said $750 for the 3090, $850 in total and a ~54-month break-even (flagged 2026-09-24). The card is $1,200-1,400 as of August 2026, so it is $1,300-1,500 and about 93-107 months.

Break-even vs ChatGPT Plus: ~93-107 months (8-9 years) Runs: Everything up to 70B with offloading

The Bottom Line

Local AI costs:

• One-time: $300-1,400 for hardware (July 2026 used prices; the memory shortage moved these a lot)
• Ongoing: $4-16/month for electricity

Cloud AI costs:

• Ongoing: $20/month (subscriptions) or variable (API)

Break-even:

• Budget setup (3060 12GB, ~$300): about 20-26 months vs ChatGPT Plus
• Mid-range setup (3090 24GB, $1,200-1,400): 10-12 years vs ChatGPT Plus (effectively never)
• Heavy API user: 2-9 months

The real value of local:

• No usage limits
• Complete privacy
• Works offline
• One-time cost, unlimited use

Read that middle row again, because it’s the one that changed. A $20/month subscription is only $20/month, and once you net out $10/month of electricity a $1,200 GPU is recovering $10 a month. That is not a payback period, it’s a hobby. Local AI still pays for itself quickly against API spend at volume, and it buys privacy, no rate limits, and offline use at any price. What it no longer does at 2026 GPU prices is beat a cheap subscription on money alone.

Start with a used RTX 3060 12GB for about $300. Run it for a year. If you were spending more than $30 a month on API calls, you’re ahead; below that, you bought privacy and offline access rather than savings. If local AI becomes essential to your workflow, upgrade to a RTX 3090 and never pay for cloud again.

Related Guides

• Budget AI PC Under $500
• GPU Buying Guide for Local AI
• Local LLMs vs ChatGPT
• Best Used GPUs for Local AI 2026
• What Can You Run on 12GB VRAM?
• Local AI Planning Tool — VRAM Calculator